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What tracking an attacker email infrastructure tells us about persistent cybercriminal operations

February 1st, 2021 No comments

From March to December 2020, we tracked segments of a dynamically generated email infrastructure that attackers used to send more than a million emails per month, distributing at least seven distinct malware families in dozens of campaigns using a variety of phishing lures and tactics. These campaigns aimed to deploy malware on target networks across the world, with notable concentration in the United States, Australia, and the United Kingdom. Attackers targeted the wholesale distribution, financial services, and healthcare industries.

By tracing these campaigns, we uncovered a sprawling infrastructure that is robust enough to seem legitimate to many mail providers, while flexible enough to allow the dynamic generation of new domain names and remain evasive. Shared IP space, domain generation algorithm (DGA) patterns, subdomains, registrations metadata, and signals from the headers of malicious emails enabled us to validate our research through overlaps in campaigns where attackers utilized multiple segments of purchased, owned, or compromised infrastructure. Using the intelligence we gathered on this infrastructure, we were at times able to predict how a domain was going to be used even before campaigns began.

This email infrastructure and the malware campaigns that use it exemplify the increasing sophistication of cybercriminal operations, driven by attackers who are motivated to use malware infections for more damaging, potentially more lucrative attacks. In fact, more recent campaigns that utilized this infrastructure distributed malware families linked to follow-on human-operated attacks, including campaigns that deployed Dopplepaymer, Makop, Clop, and other ransomware families.

Our deep investigation into this infrastructure brings to light these important insights about persistent cybercriminal operations:

  • Tracking an email infrastructure surfaces patterns in attacker activity, bubbling up common elements in seemingly disparate campaigns
  • Among domains that attackers use for sending emails, distributing malware, or command-and-control, the email domains are the most likely to share basic registration similarities and more likely to use DGA
  • Malware services rely on proxy providers to make tracking and attribution difficult, but the proxies themselves can provide insights into upcoming campaigns and improve our ability to proactively protect against them
  • Gaining intelligence on email infrastructures enables us to build or improve proactive and comprehensive protections like those provided by Microsoft Defender for Office 365 to defend against some of the world’s most active malware campaigns

While there is existing in-depth research into some of these specific campaigns, in this blog we’ll share more findings and details on how email distribution infrastructures drive some of the most prevalent malware operations today. Our goal is to provide important intelligence that hosting providers, registrars, ISPs, and email protection services can use and build on to protect customers from the threats of today and the future. We’ll also share insights and context to empower security researchers and customers to take full advantage of solutions like Microsoft Defender for Office 365 to perform deep investigation and hunting in their environment and make their organizations resilient against attacks.

The role of for-sale infrastructure services in the threat ecosystem

We spotted the first segment of the infrastructure in March, when multiple domains were registered using distinct naming patterns, including the heavy use of the word “strange”, inspiring the name StrangeU. In April, a second segment of the infrastructure, one that used domain generation algorithm (DGA), began registration as well. We call this segment RandomU.

The emergence of this infrastructure in March dovetailed with the disruption of the Necurs botnet that resulted in the reduction of service. Before being disrupted, Necurs was one of the world’s largest botnets and was used by prolific malware campaign operators such as those behind Dridex. For-sale services like Necurs enable attackers to invest in malware production while leasing the delivery components of their activities to further obfuscate their behavior. The StrangeU and RandomU infrastructure appear to fill in the service gap that the Necurs disruption created, proving that attackers are highly motivated to quickly adapt to temporary interruptions to their operations.

Graph showing timeline of the Necurs takedown and the staging and operation of StrangeU and RandomU

Figure 1. Timeline of staging and utilization of the email infrastructure

At first, the new email infrastructure was used infrequently in campaigns that distributed highly commodity malware like Mondfoxia and Makop. Soon, however, it attracted the attention of Dridex and Trickbot operators, who began using the infrastructure for portions of their campaigns, sometimes entirely and sometimes mixed with other compromised infrastructure or email providers.

Analyzing these mail clusters provides insight into how human the tangled web of modular attacker infrastructure remains. From unifying key traits in registration and behavior to the simple and effective techniques that the wide variety of malware uses, attackers’ goals in this diversification point toward combatting automated analysis. However, these same shared characteristics and methods translate to insights that inform resilient protections that defend customers against these attacks.

Domain registration and email infrastructure staging

On March 7, 2020, attackers began registering a series of domains with Namecheap using sets of stolen email addresses, largely from free email services like mail.com, mail.ru, list.ru, and others. These domains all had similar characteristics that could be linked back to various similarities in registration. Almost all of the registered domains contained the word “strange” and were under the .us TLD, hence the name StrangeU. The use of .us TLD prevented domain or WHOIS privacy services—often used to obfuscate domain ownership and provenance—which are prohibited for this TLD.

To circumvent tracking and detection of these domains, attackers used false registration metadata. However, there was heavy crossover in the fake names and email addresses, allowing us to find additional domain names, some of which could be tied together using other keywords as shown in the list below, and fingerprint the domain generation mechanism.

The StrangeU domains were registered in early March 2020 and operated in continuous small bursts until April, when they were used for a large ransomware campaign. Following that, a new campaign occurred fairly regularly every few weeks. Registration of new domains continued throughout the year, and in September, the StrangeU infrastructure was used in conjunction with a similar infrastructure to deliver Dridex, after which these domains were used less frequently.

This second mailing segment, RandomU, employed a different DGA mechanism but still utilized Namecheap and showed a more consistent through line of registration metadata than its StrangeU counterpart. This infrastructure, which surfaced in April, was used infrequently through the Spring, with a surge in May and July. After the Dridex campaign in September in which it was used along with StrangeU, it has been used in two large Dridex campaigns every month.

Table listing observed patterns in StrangeU and RandomU infrastructures

Figure 2. Common patterns in domains belonging to the email infrastructure

The StrangeU and RandomU segments of domains paint a picture of supplementing modular mailing services that allowed attackers to launch region-specific and enterprise-targeting attacks at scale, delivering over six million emails. The two segments contained a standard barrage of mailing subdomains, with over 60 unique subdomains referencing email across clusters, consistent with each other, with each domain having four to five subdomains. The following is a sample of malware campaigns, some of which we discuss in detail in succeeding sections, that we observed this infrastructure was used for:

  • Korean spear-phishing campaigns that delivered Makop ransomware in April and June
  • Emergency alert notifications that distributed Mondfoxia in April
  • Black Lives Matter lure that delivered Trickbot in June
  • Dridex campaign delivered through StrangeU and other infra from June to July
  • Dofoil (SmokeLoader) campaign in August
  • Emotet and Dridex activities in September, October, and November

Timeline of campaigns using the StrangeU and RandomU infrastructures

Figure 3. Timeline of campaigns that used StrangeU and RandomU domains

Korean spear-phishing delivers Makop ransomware (April and June 2020)

In early April, StrangeU was used to deliver the Makop ransomware. The emails were sent to organizations that had major business operations in Korea and used names of Korean companies as display names. Signals from Microsoft Defender for Office 365 indicated that these campaigns ran in short bursts.

The emails had .zip attachments containing executables with file names that resembled resumes from job seekers. Once a user opened the attachments, the executables delivered Makop, a ransomware-as-a-service (RaaS) payload that targeted devices and backups.

Upon infection, the malware quickly used the WMI command-line (WMIC) utility and deleted shadow copies. It then used the BCEdit tool and altered the boot configuration to ignore future failures and prevent restoration before encrypting all files and renaming them with .makop extensions.

The second time we observed the campaign almost two months later, in early June, the attackers used a Makop ransomware variant with many modified elements, including added persistence via scripts in the Startup folder before triggering a reboot.

Nearly identical attempts to deliver Makop using resume-based lures were covered by Korean security media during the entire year, using popular mail services through legitimate vendors like Naver and Hanmail. This could indicate that during short bursts the Makop operators were unable to launch their campaigns through legitimate services and had to move to alternate infrastructures like StrangeU instead.

Black Lives Matter lure delivers Trickbot (June 2020)

One campaign associated with the StrangeU infrastructure gained notoriety in mid-June for its lure as well as for delivering the notorious info-stealing malware Trickbot. This campaign circulated emails with malicious Word documents claiming to seek anonymous input on the Black Lives Matter movement.

An initial version of this campaign was observed on June 10 sending emails from a separate, unique attacker-owned mailing infrastructure using .monster domains. However, in the next iteration almost two weeks later, the campaign delivered emails from various domains specifically created with the Black Lives Matter signage, interspersed with StrangeU domains:

  • b-lives-matter[.]site
  • blivesm[.]space
  • blivesmatter[.]site
  • lives-matter-b[.]xyz
  • whoslivesmatter[.]site
  • lives-m-b[.]xyz
  • ereceivedsstrangesecureworld[.]us
  • b-l-m[.]site

Both campaigns carried the same Trickbot payload, operated for two days, and used identical post-execution commands and callouts to compromised WordPress sites.

Once a user opened the document attachment and enabled the malicious macro, Word launched cmd.exe with the command “/c pause” to evade security tools that monitored for successive launches of multiple processes. It then launched commands that deleted proxy settings in preparation for connecting to multiple C2 IP addresses.

Screenshot of malicious document

Figure 4. Screenshot of the malicious document used to deliver Trickbot

The commands also launched rundll32.exe, a native binary commonly used as a living-off-the-land binary, to load a malicious file in memory. The commandeered rundll32.exe also proceeded to perform other tasks using other living-off-the-land binaries, including wermgr.exe and svchost.exe.

In turn, the hijacked wermgr.exe process dropped a file with a .dog extension that appeared to be the Trickbot payload. The same instance of wermgr.exe then appeared to inject code into svchost.exe and scanned for open SMB ports on other devices. The commandeered svchost.exe used WMI to open connections to additional devices on the network, while continuing to collect data from the initial infected device. It also opened multiple browsers on localhost connections to capture browser history and other information via esentutl.exe and grabber_temp.edb, both of which are often used by the Trickbot malware family.

This campaign overwhelmingly targeted corporate accounts in the United States and Canada and avoided individual accounts. Despite heavy media coverage, this campaign was relatively small, reflecting a common behavior among cybercrime groups, which often run multiple, dynamic low-volume campaigns designed to evade resilient detection.

Dridex campaigns big and small (June to July 2020 and beyond)

From late June through July, Dridex operators ran numerous campaigns that distributed Excel documents with malicious macros to infect devices. These operators first delivered emails through the StrangeU infrastructure only, but they quickly started to use compromised email accounts of legitimate organizations as well, preventing defenders from easily blocking deliveries. Despite this, emails from either StrangeU or the compromised accounts had overlapping attributes. For example, many of the emails used the same Reply To addresses that were sourced from compromised individual accounts and not consistent with the sender addresses.

During the bulk of this run, Excel files were attached directly in the email in order to eventually pull the Dridex payload from .xyz domains such as those below. The attackers changed the delivery domains every few days and connected to IP-based C2s on familiar ports like 4664, 3889, 691, and 8443:

  • yumicha[.]xyz
  • rocesi[.]xyz
  • secretpath[.]xyz
  • guruofbullet[.]xyz
  • Greyzone[.]xyz

When opened, the Excel document installed one of a series of custom Dridex executables downloaded from the attacker C2 sites. Like most variants in this malware family, the custom Dridex executables incorporated code loops, time delays, and environment detection mechanisms that evaded numerous public and enterprise sandboxes.

Dridex is known for its capability to perform credential theft and establish connectivity to attacker infrastructure. In this instance, the same Dridex payload was circulated daily using varying lures, often repeatedly to the same organizations to ensure execution on target networks.

During the longer and more stable Excel Dridex campaigns in June and July, a Dridex variant was also distributed in much smaller quantities utilizing Word documents over a one-day period, perhaps testing new evasion techniques. These Word documents, while still delivering Dridex, improved existing obfuscation methods using a unique combination of VBA stomping and replacing macros and function calls with arbitrary text. In a few samples of these documents, we found text from Shakespearean prose.

</ms:script>   
var farewell_and_moon = ["m","a","e","r","t","s",".","b","d","o","d","a"].reverse().join("")   
a_painted_word(120888)   
function as_thy_face(takes_from_hamlet)   
{return new ActiveXObject(takes_from_hamlet)}   
</ms:script>

While Microsoft researchers didn’t observe this portion of the campaign moving into the human-operated phase—targets did not open the attachment—this campaign was likely to introduce tools like PowerShell Empire or Cobalt Strike to steal credentials, move laterally, and deploy ransomware.

Emotet, Dridex, and the RandomU infrastructure (September and beyond)

Despite an errant handful of deliveries distributing Dofoil (also known as SmokeLoader) and other malware, the vast majority of the remaining deliveries through StrangeU have been Dridex campaigns that reoccured every few weeks for a handful of days at a time. These campaigns started on September 7, when RandomU and StrangeU were notably used in a single campaign, after which StrangeU began to see less utilization.

These Dridex campaigns utilized an Emotet loader and initial infrastructure for hosting, allowing the attackers to conduct a highly modular email campaign that delivered multiple distinct links to compromised domains. These domains employed heavy sandbox evasion and are connected by a series of PHP patterns ending in a small subset of options: zxlbw.phpyymclv.phpzpsxxla.php, or app.php. As the campaigns continued, the PHP was dynamically generated, adding other variants, including vary.php, invoice.php, share.php, and many others. Some examples are below.

  • hxxps://molinolafama[.]com[.]mx/app[.]php
  • hxxps://meetingmins[.]com/app[.]php
  • hxxps://contrastmktg[.]com/yymclv[.]php
  • hxxps://idklearningcentre[.]com[.]ng/zxlbw[.]php
  • hxxps://idklearningcentre[.]com[.]ng/zpsxxla[.]php
  • hxxps://idklearningcentre[.]com[.]ng/yymclv[.]php
  • hxxps://hsa[.]ht/yymclv[.]php
  • hxxps://hsa[.]ht/zpsxxla[.]php
  • hxxps://hsa[.]ht/zxlbw[.]php
  • hxxps://contrastmktg[.]com/yymclv[.]php
  • hxxps://track[.]topad[.]co[.]uk/zpsxxla[.]php
  • hxxps://seoemail[.]com[.]au/zxlbw[.]php
  • hxxps://bred[.]fr-authentification-source-no[.]inaslimitada[.]com/zpsxxla[.]php
  • hxxp://www[.]gbrecords[.]london/zpsxxla[.]php
  • hxxp://autoblogsite[.]com/zpsxxla[.]php
  • hxxps://thecrossfithandbook[.]com/zpsxxla[.]php
  • hxxps://mail[.]168vitheyrealestate[.]com/zpsxxla[.]php

In this campaign, sandboxes were frequently redirected to unrelated sites like chemical manufacturers or medical suppliers, while users received an Emotet downloader within a Word document, which once again used macros to facilitate malicious activities.

Screenshot of malicious document

Figure 5. Screenshot of the malicious document used to deliver Dridex

The malicious macro utilized WMI to run a series of standard PowerShell commands. First, it downloaded the executable payload itself by contacting a series of C2 domains associated with Emotet campaigns since July. Afterward, additional encoded PowerShell commands were used in a similar fashion to download a .zip file that contained a Dridex DLL. Additional commands also reached out to a variety of Emotet infrastructure hosted on compromised WordPress administrative pages, even after the Dridex payload has already been downloaded. Dridex then modified RUN keys to automatically start the Dridex executable, which was renamed to riched20.exe on subsequent logons.

We also observed simultaneous connections to associated Dridex and Emotet infrastructure. These connections were largely unencrypted and occurred over a variety of ports and services, including ports 4664 and 9443. At this point the malware had firm presence on the machine, enabling attackers to perform human-operated activity at a later date.

In the past, reports have confirmed Dridex being delivered via leased Emotet infrastructure. There have also been many IP and payload-based associations. This research adds to that body of work and confirms additional associations via namespace, as well as correlation of email lure, metadata, and sender. This iteration of campaign repeated through October to December largely unchanged with nearly identical mails.

Defending organizations against malware campaigns

As attacks continue to grow in modularity, the tactics that attackers use to deliver phishing email, gain initial access on systems, and move laterally will continuously become more varied. This research shows that despite these disparities and the increased resiliency attackers have built, the core tactics and tools that they use are still limited in scope, relying repeatedly on familiar malicious macros, lures, and sending tactics.

Sweeping research into massive attacker infrastructures, as well as our real-time monitoring of malware campaigns and attacker activity, directly inform Microsoft security solutions, allowing us to build or improve protections that block malware campaigns and other email threats, both current and future, as well as provide enterprises with the tools for investigating and responding to email campaigns in real-time.

Microsoft delivers these capabilities through Microsoft Defender for Office 365. Features likes Safe attachments and Safe links ensure real-time, dynamic protection against email campaigns no matter the lure or evasion tactic. These features use a combination of detonation, automated analysis, and machine learning to detect new and unknown threats. Meanwhile, the Campaign view shows the complete picture of email campaigns as they happen, including timelines, sending patterns, impact to the organization, and details like IP addresses, senders, and URLs. These insights into email threats empower security operations teams to respond to attacks, perform additional hunting, and fix configuration issues.

Armed with an advanced solution like Microsoft Defender for Office 365 and the rest of technologies in the broader Microsoft 365 Defender solution, enterprises can further increase resilience against threats by following these recommendations:

  • Educate end users about protecting personal and business information in social media, filtering unsolicited communication, identifying lures in spear-phishing email, and reporting of reconnaissance attempts and other suspicious activity.
  • Configure Office 365 email filtering settings to ensure blocking of phishing & spoofed emails, spam, and emails with malware. Set Office 365 to recheck links on click and delete sent mail to benefit from newly acquired threat intelligence.
  • Disallow macros or allow only macros from trusted locations. See the latest security baselines for Office and Office 365.
  • Turn on AMSI for Office VBA.
  • Check perimeter firewall and proxy to restrict servers from making arbitrary connections to the internet to browse or download files. Turn on network protection to block connections to malicious domains and IP addresses. Such restrictions help inhibit malware downloads and command-and-control activity.

Turning on attack surface reduction rules, including rules that can block advanced macro activity, executable content, process creation, and process injection initiated by Office applications, also significantly improves defenses. The following rules are especially useful in blocking the techniques observed in campaigns using the StrangeU and RandomU infrastructure:

Microsoft 365 customers can also use the advanced hunting capabilities in Microsoft 365 Defender, which integrates signals from Microsoft Defender for Office 365 and other solutions, to locate activities and artifacts related to the infrastructure and campaigns discussed in this blog. These queries can be used with advanced hunting in Microsoft 365 security center, but the same regex pattern can be used on other security tools to identify or block emails.

This query searches for emails sent from StrangeUemail addresses. Run query

EmailEvents   
| where SenderMailFromDomain matches regex @"^(?:eraust|ereply|reply|ereceived|received|reaust|esend|inv|send|emailboost|eontaysstrange|eprop|frost|eont|servicply).*(strange|stange|emailboost).*\.us$"   
or SenderFromDomain matches regex @"^(?:eraust|ereply|reply|ereceived|received|reaust|esend|inv|send|emailboost|eontaysstrange|eprop|frost|eont|servicply).*(strange|stange|emailboost).*\.us$"

Learn how you can stop attacks through automated, cross-domain security and built-in AI with Microsoft Defender 365.

 

 

Indicators of compromise

StrangeU domains

esendsstrangeasia[.]us sendsstrangesecuretoday[.]us emailboostgedigital[.]us
emailboostgelife[.]us emailboostgelifes[.]us emailboostgesecureasia[.]us
eontaysstrangeasia[.]us eontaysstrangenetwork[.]us eontaysstrangerocks[.]us
eontaysstrangesecureasia[.]us epropivedsstrangevip[.]us ereplyggstangeasia[.]us
ereplyggstangedigital[.]us ereplyggstangeereplys[.]us ereplyggstangelifes[.]us
ereplyggstangenetwork[.]us ereplyggstangesecureasia[.]us frostsstrangeworld[.]us
servicceivedsstrangevip[.]us servicplysstrangeasia[.]us servicplysstrangedigital[.]us
servicplysstrangelife[.]us servicplysstrangelifes[.]us servicplysstrangenetwork[.]us
ereceivedsstrangesecureworld[.]us ereceivedsstrangetoday[.]us ereceivedsstrangeus[.]us
esendsstrangesecurelife[.]us sendsstrangesecureesendss[.]us ereplysstrangesecureasia[.]us
ereplysstrangesecurenetwork[.]us receivedsstrangesecurelife[.]us ereplysstrangeworld[.]us
reauestysstrangesecurelive[.]us ereceivedsstrangeworld[.]us esendsstrangesecurerocks[.]us
reauestysstrangesecuredigital[.]us reauestysstrangesecurenetwork[.]us reauestysstrangesecurevip[.]us
replysstrangesecurelife[.]us ereauestysstrangesecurerocks[.]us ereceivedsstrangeasia[.]us
ereceivedsstrangedigital[.]us ereceivedsstrangeereceiveds[.]us ereceivedsstrangelife[.]us
ereceivedsstrangelifes[.]us ereceivedsstrangenetwork[.]us ereceivedsstrangerocks[.]us
ereceivedsstrangesecureasia[.]us receivedsstrangeworld[.]us replysstrangedigital[.]us
invdeliverynows[.]us esendsstrangesecuredigital[.]us esendsstrangesecureworld[.]us
sendsstrangesecurenetwork[.]us ereceivedsstrangevip[.]us replysstrangerocs[.]us
replysstrangesecurelive[.]us invpaymentnoweros[.]us invpaymentnowes[.]us
replysstrangeracs[.]us reauestysstrangesecurebest[.]us receivedsstrangesecurebest[.]us
reauestysstrangesecurelife[.]us ereplysstrangevip[.]us reauestysstrangesecuretoday[.]us
ereplysstrangesecureus[.]us ereplysstrangetoday[.]us ereceivedsstrangesecuredigital[.]us
ereceivedsstrangesecureereceiveds[.]us ereceivedsstrangesecurelife[.]us ereceivedsstrangesecurenetwork[.]us
ereceivedsstrangesecurerocks[.]us ereceivedsstrangesecureus[.]us ereceivedsstrangesecurevip[.]us
sendsstrangesecurebest[.]us sendsstrangesecuredigital[.]us sendsstrangesecurelive[.]us
sendsstrangesecureworld[.]us esendsstrangedigital[.]us esendsstrangeesends[.]us
esendsstrangelifes[.]us esendsstrangerocks[.]us esendsstrangesecureasia[.]us
esendsstrangesecureesends[.]us esendsstrangesecurenetwork[.]us esendsstrangesecureus[.]us
esendsstrangesecurevip[.]us esendsstrangevip[.]us ereauestysstrangesecureasia[.]us
ereplysstrangeasia[.]us ereplysstrangedigital[.]us ereplysstrangeereplys[.]us
ereplysstrangelife[.]us ereplysstrangelifes[.]us ereplysstrangenetwork[.]us
ereplysstrangerocks[.]us ereplysstrangesecuredigital[.]us ereplysstrangesecureereplys[.]us
ereplysstrangesecurelife[.]us ereplysstrangesecurerocks[.]us ereplysstrangesecurevip[.]us
ereplysstrangesecureworld[.]us ereplysstrangeus[.]us reauestysstrangesecureclub[.]us
reauestysstrangesecureereauestyss[.]us reauestysstrangesecureworld[.]us receivedsstrangesecureclub[.]us
receivedsstrangesecuredigital[.]us receivedsstrangesecureereceivedss[.]us receivedsstrangesecurelive[.]us
receivedsstrangesecurenetwork[.]us receivedsstrangesecuretoday[.]us receivedsstrangesecurevip[.]us
receivedsstrangesecureworld[.]us replysstrangesecurebest[.]us replysstrangesecureclub[.]us
replysstrangesecuredigital[.]us replysstrangesecureereplyss[.]us replysstrangesecurenetwork[.]us
replysstrangesecuretoday[.]us replysstrangesecurevip[.]us replysstrangesecureworld[.]us
sendsstrangesecurevip[.]us esendsstrangelife[.]us esendsstrangenetwork[.]us
esendsstrangetoday[.]us esendsstrangeus[.]us esendsstrangeworld[.]us
sendsstrangesecureclub[.]us sendsstrangesecurelife[.]us plysstrangelifes[.]us
intulifeinoi[.]us replysstrangerocks[.]us invpaymentnowe[.]us
replysstrangelifes[.]us replysstrangenetwork[.]us invdeliverynowr[.]us
ereceivedggstangevip[.]us ereplyggstangerocks[.]us servicceivedsstrangeworld[.]us
servicplysstrangesecureasia[.]us servicplysstrangeservicplys[.]us emailboostgeasia[.]us
emailboostgeereplys[.]us emailboostgenetwork[.]us emailboostgerocks[.]us
eontaysstrangedigital[.]us eontaysstrangeeontays[.]us eontaysstrangelife[.]us
eontaysstrangelifes[.]us epropivedsstrangeworld[.]us ereceivedggstangeworld[.]us
ereplyggstangelife[.]us frostsstrangevip[.]us servicplysstrangerocks[.]us
invdeliverynow[.]us invpaymentnowlife[.]us invdeliverynowes[.]us
invpaymentnowwork[.]us replysstrangedigitals[.]us replysstrangelife[.]us
replysstrangelifee[.]us replystrangeracs[.]us

RandomU domains

cnewyllansf[.]us kibintiwl[.]us planetezs[.]us sakgeldvi[.]us
rdoowvaki[.]us kabelrandjc[.]us wembaafag[.]us postigleip[.]us
jujubugh[.]us honidefic[.]us utietang[.]us scardullowv[.]us
vorlassebv[.]us jatexono[.]us vlevaiph[.]us bridgetissimema[.]us
schildernjc[.]us francadagf[.]us strgatibp[.]us jelenskomna[.]us
prependerac[.]us oktagonisa[.]us enjaularszr[.]us opteahzf[.]us
skaplyndiej[.]us dirnaichly[.]us kiesmanvs[.]us gooitounl[.]us
izvoznojai[.]us kuphindanv[.]us pluienscz[.]us huyumajr[.]us
arrutisdo[.]us loftinumkx[.]us ffermwyrzf[.]us hectorfranez[.]us
munzoneia[.]us savichicknc[.]us nadurogak[.]us raceaddicteg[.]us
mpixiris[.]us lestenas[.]us collahahhaged[.]us enayilebl[.]us
hotteswc[.]us kupakiliayw[.]us deroutarek[.]us pomagatia[.]us
mizbebzpe[.]us firebrandig[.]us univerzamjw[.]us amigosenrutavt[.]us
kafrdaaia[.]us cimadalfj[.]us ubrzanihaa[.]us yamashumiks[.]us
jakartayd[.]us cobiauql[.]us idiofontg[.]us hoargettattzt[.]us
encilips[.]us dafanapydutsb[.]us intereqr[.]us chestecotry[.]us
diegdoceqy[.]us ffwdenaiszh[.]us sterinaba[.]us wamwitaoko[.]us
peishenthe[.]us hegenheimlr[.]us educarepn[.]us ayajuaqo[.]us
imkingdanuj[.]us dypeplayentqt[.]us traktorkaqk[.]us prilipexr[.]us
collazzird[.]us sentaosez[.]us vangnetxh[.]us valdreska[.]us
mxcujatr[.]us angelqtbw[.]us bescromeobsemyb[.]us hoogametas[.]us
mlitavitiwj[.]us pasgemaakhc[.]us facelijaxg[.]us harukihotarugf[.]us
pasosaga[.]us mashimariokt[.]us vodoclundqs[.]us trofealnytw[.]us
cowboyie[.]us dragovanmm[.]us jonuzpura[.]us cahurisms[.]us
leetzetli[.]us jonrucunopz[.]us flaaksik[.]us wizjadne[.]us
zatsopanogn[.]us roblanzq[.]us barbwirelx[.]us givolettoan[.]us
gyfarosmt[.]us zastirkjx[.]us sappianoyv[.]us noneedfordayvnb[.]us
andreguidiao[.]us concubinsel[.]us meljitebj[.]us alcalizezsc[.]us
springenmw[.]us kongovkamev[.]us starlitent[.]us cassineraqy[.]us
ariankacf[.]us plachezxr[.]us abulpasastq[.]us scraithehk[.]us
wintertimero[.]us abbylukis[.]us lumcrizal[.]us trokrilenyr[.]us
skybdragonqx[.]us pojahuez[.]us rambalegiec[.]us relucrarebk[.]us
vupardoumeip[.]us punicdxak[.]us vaninabaranaogw[.]us yesitsmeagainle[.]us
upcominge[.]us arwresaub[.]us zensimup[.]us joelstonem[.]us
ciflaratzz[.]us adespartc[.]us maaltijdr[.]us acmindiaj[.]us
mempetebyj[.]us itorandat[.]us galenicire[.]us cheldisalk[.]us
zooramawpreahkt[.]us sijamskojoc[.]us fliefedomrr[.]us ascenitianyrg[.]us
tebejavaaq[.]us finnerssshu[.]us slimshortyub[.]us angstigft[.]us
avedaviya[.]us aasthakathykh[.]us nesklonixt[.]us drywelyza[.]us
paginomxd[.]us gathesitehalazw[.]us antinodele[.]us ferestat[.]us
tianaoeuat[.]us pogilasyg[.]us mjawxxik[.]us bertolinnj[.]us
auswalzenna[.]us mmmikeyvb[.]us megafonasgc[.]us litnanjv[.]us
boockmasi[.]us andreillazf[.]us vampirupn[.]us lionarivv[.]us
ihmbklkdk[.]us okergeeliw[.]us forthabezb[.]us trocetasss[.]us
kavamennci[.]us mipancepezc[.]us infuuslx[.]us dvodomnogeg[.]us
zensingergy[.]us eixirienhj[.]us trapunted[.]us greatfutbolot[.]us
porajskigx[.]us mumbleiwa[.]us cilindrarqe[.]us uylateidr[.]us
sdsandrahuin[.]us trapeesr[.]us trauttbobw[.]us bostiwro[.]us
niqiniswen[.]us ditionith[.]us folseine[.]us zamoreki[.]us
sonornogae[.]us xlsadlxg[.]us varerizu[.]us seekabelv[.]us
nisabooz[.]us pohvalamt[.]us inassyndr[.]us ivenyand[.]us
karbonsavz[.]us svunturc[.]us babyrosep[.]us aardigerf[.]us
fedrelandx[.]us degaeriah[.]us detidiel[.]us acuendoj[.]us
peludine[.]us impermatav[.]us datsailis[.]us melenceid[.]us
beshinon[.]us dinangnc[.]us fowiniler[.]us laibstadtws[.]us
bischerohc[.]us muctimpubwz[.]us jusidalikan[.]us peerbalkw[.]us
robesikaton[.]us thabywnderlc[.]us osoremep[.]us krlperuoe[.]us
ntarodide[.]us bideoskin[.]us senagena[.]us kelyldori[.]us
kawtriatthu[.]us rbreriaf[.]us enaqwilo[.]us monesine[.]us
onwinaka[.]us yonhydro[.]us siostailpg[.]us bannasba[.]us
milosnicacz[.]us tunenida[.]us sargasseu[.]us malayabc[.]us
prokszacd[.]us premarketcl[.]us zedyahai[.]us xinarmol[.]us
minttaid[.]us pufuletzpb[.]us nekbrekerdv[.]us ppugsasiw[.]us
katarkamgm[.]us kyraidaci[.]us falhiblaqv[.]us lisusant[.]us
mameriar[.]us quslinie[.]us nirdorver[.]us trocairasec[.]us
pochwikbz[.]us ingykhat[.]us okrzynjf[.]us razsutegayl[.]us
dimbachzx[.]us buchingmc[.]us iessemda[.]us fatarelliqi[.]us
efetivumd[.]us vdevicioik[.]us klumppwha[.]us stefiensi[.]us
donetzbx[.]us wetafteto[.]us denementnd[.]us cyllvysr[.]us
viweewmokmt[.]us destescutyi[.]us craulisrt[.]us maggiebagglesxt[.]us
yawapasaqi[.]us spimilatads[.]us paseadoryy[.]us apageyantak[.]us
magicofaloeaj[.]us prefatoryhe[.]us statvaiq[.]us piketuojaqk[.]us
mushipotatobt[.]us suergonugoy[.]us gummiskoxt[.]us torunikc[.]us
adoleishswn[.]us rovljanie[.]us ivicukfa[.]us vajarelliwe[.]us
burksuit[.]us adoraableio[.]us bassettsz[.]us chevyguyxq[.]us
lunamaosa[.]us telemovelmi[.]us pimptazticui[.]us posteryeiq[.]us
miriamloiso[.]us salahlekajl[.]us inveshilifj[.]us alquicelbi[.]us
hitagjafirt[.]us ohatranqm[.]us scosebexgofxu[.]us vivalasuzyygb[.]us
lugleeghp[.]us alicuppippn[.]us wedutuanceseefv[.]us abnodobemmn[.]us
zajdilxtes[.]us inhaltsqxw[.]us rejtacdat[.]us contunaag[.]us
pitajucmas[.]us delopezmc[.]us donjimafx[.]us iheartcoxlc[.]us
rommelcrxgi[.]us jorguetky[.]us jadesellvb[.]us fintercentrosfs[.]us
ralbarix[.]us kynnirinnty[.]us bibulbio[.]us aspazjagh[.]us
gleboqrat[.]us tensinory[.]us usitniterx[.]us zaretkyui[.]us
hentugustqy[.]us surigatoszuk[.]us nitoeranybr[.]us spitzkopuo[.]us
podkarpatruszz[.]us milfincasqo[.]us datatsbjew[.]us changotme[.]us
losbindebt[.]us ninjachuckvb[.]us desfadavacp[.]us potkazatiun[.]us
sernakct[.]us razmersat[.]us purtinaah[.]us ampiovfa[.]us
durstinyskv[.]us kreukenct[.]us shinanyavc[.]us kolaryta[.]us
yangtsekk[.]us voyagedeviema[.]us elblogdelld[.]us utiligijc[.]us
peaplesokqo[.]us jenggoteq[.]us dogliairler[.]us kandizifb[.]us
flunkmasteraz[.]us clewpossejj[.]us hymgaledaja[.]us gmckayar[.]us
fagordul[.]us pnendickhs[.]us arrogede[.]us stilenii[.]us
cafelireao[.]us poishiuuz[.]us nonfunccoupyo[.]us madrigalbta[.]us
tarad[.]us sarahcp[.]us wickyjr[.]us ghadrn[.]us
sirvond[.]us qumarta[.]us verow[.]us mondeki[.]us
lirana[.]us niarvi[.]us belena[.]us qucono[.]us
ulianag[.]us lenut[.]us shivave[.]us jendone[.]us
seddauf[.]us jarare[.]us uchar[.]us ealesa[.]us
wyoso[.]us marnde[.]us thiath[.]us aulax[.]us
bobelil[.]us jestem[.]us detala[.]us phieyen[.]us
annazo[.]us dilen[.]us jelan[.]us ipedana[.]us
keulsph[.]us ztereqm[.]us rinitan[.]us natab[.]us
haritol[.]us ricould[.]us lldra[.]us miniacs[.]us
zahrajr[.]us cayav[.]us pheduk[.]us qugagad[.]us
dehist[.]us letama[.]us mencyat[.]us vindae[.]us
uranc[.]us handil[.]us galezay[.]us bamerna[.]us
yllyn[.]us ckavl[.]us ilalie[.]us daellee[.]us
cuparoc[.]us zelone[.]us burnile[.]us uloryrt[.]us
shexo[.]us phalbe[.]us hanolen[.]us lorria[.]us
beten[.]us xuserye[.]us iclelan[.]us cwokas[.]us
vesic[.]us ontolan[.]us wajdana[.]us telama[.]us
missani[.]us usinaye[.]us ertanom[.]us kericex[.]us
denaga[.]us tyderq[.]us seliza[.]us kinnco[.]us
qurtey[.]us arzenitlu[.]us vellpoildzu[.]us keityod[.]us
ltangerineldf[.]us lizergidft[.]us serrucheah[.]us lolricelolad[.]us
expiantaszg[.]us hljqfyky[.]us abarrosch[.]us lepestrinynr[.]us
elektroduendevq[.]us waggonbauwh[.]us chaquetzgg[.]us revizijiqa[.]us
ziggyiqta[.]us rokenounkaf[.]us lottemanvl[.]us corsetatsvp[.]us
extasiatny[.]us darkinjtat[.]us pastorsta[.]us sategnaxf[.]us
mordiquedp[.]us mogulanbub[.]us aleesexx[.]us strekktumgz[.]us
kresanike[.]us oberhirtesn[.]us wyddiongw[.]us etherviltjd[.]us
gdinauq[.]us tumisolcv[.]us oardbzta[.]us zamislimrx[.]us
tidifkil[.]us anwirbtda[.]us breliaattainoqt[.]us steinzeitps[.]us
grafoay[.]us shuramiok[.]us sanarteau[.]us jerininomgv[.]us
kusturirp[.]us tenisaragonpu[.]us terquezajf[.]us remularegf[.]us
nobanior[.]us julijmc[.]us dekrapp[.]us odaljenakd[.]us

 

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Threat actor leverages coin miner techniques to stay under the radar – here’s how to spot them

November 30th, 2020 No comments

Cryptocurrency miners are typically associated with cybercriminal operations, not sophisticated nation state actor activity. They are not the most sophisticated type of threats, which also means that they are not among the most critical security issues that defenders address with urgency. Recent campaigns from the nation-state actor BISMUTH take advantage of the low-priority alerts coin miners cause to try and fly under the radar and establish persistence.

BISMUTH, which shares similarities with OceanLotus or APT32, has been running increasingly complex cyberespionage attacks as early as 2012, using both custom and open-source tooling to target large multinational corporations, governments, financial services, educational institutions, and human and civil rights organizations. But in campaigns from July to August 2020, the group deployed Monero coin miners in attacks that targeted both the private sector and government institutions in France and Vietnam.

Because BISMUTH’s attacks involved techniques that ranged from typical to more advanced, devices with common threat activities like phishing and coin mining should be elevated and inspected for advanced threats. More importantly, organizations should prioritize reducing attack surface and hardening networks against the full range of attacks. In this blog, we’ll provide in-depth technical details about the BISMUTH attacks in July and August 2020 and mitigation recommendations for building organizational resilience.

While this actor’s operational goals remained the same—establish continuous monitoring and espionage, exfiltrating useful information as is it surfaced—their deployment of coin miners in their recent campaigns provided another way for the attackers to monetize compromised networks. Considering some of the group’s traditional targets are human and civil rights organizations, BISMUTH attacks demonstrate how attackers give little regard to services they impact.

The use of coin miners by BISMUTH was unexpected, but it was consistent with the group’s longtime methods of blending in. This pattern of blending in is particularly evident in these recent attacks, starting from the initial access stage: spear-phishing emails that were specially crafted for one specific recipient per target organization and showed signs of prior reconnaissance. In some instances, the group even corresponded with the targets, building even more believability to convince targets to open the malicious attachment and start the infection chain.

The other way that BISMUTH attempted to blend in and hide in plain sight was the heavy use of DLL side-loading, a technique in which a legitimate DLL is replaced with a malicious one so that the latter is loaded when the associated application is run. In their recent attacks, BISMUTH utilized copies of various legitimate software to load malicious DLL files and perform tasks in the context of these legitimate applications. To perform DLL sideloading, BISMUTH introduced outdated versions of various applications, including Microsoft Defender Antivirus. They also leveraged the Sysinternals DebugView tool, the McAfee on-demand scanner, and Microsoft Word 2007.

Blending in was important for BISMUTH because the group spent long periods of time performing discovery on compromised networks until they could access and move laterally to high-value targets like servers, where they installed various tools to further propagate or perform more actions. At this point in the attack, the group relied heavily on evasive PowerShell scripts, making their activities even more covert.

The coin miners also allowed BISMUTH to hide its more nefarious activities behind threats that may be perceived to be less alarming because they’re “commodity” malware. If we learned anything from “commodity” banking trojans that bring in human-operated ransomware, we know that common malware infections can be indicators of more sophisticated cyberattacks and should be treated with urgency and investigated and resolved comprehensively.

Diagram showing BISMUTH attacker techniques across attack stages

Initial access

BISMUTH attempted to gain initial access by sending specially crafted malicious emails from a Gmail account that appears to have been made specifically for this campaign. It’s likely the group conducted reconnaissance using publicly available sources and chose individual targets based on their job function. Each email was sent to only one recipient at each target organization and used tailored subject lines and lure themes, for example:

  • Dự thảo hợp đồng (translates from Vietnamese to “Draft Contract”)
  • Ứng tuyển – Trưởng ban nghiên cứu thị trường (translates from Vietnamese to “Application form – Head of Market Research”)

Of note, the group sent several replies to one of these emails, which indicated that they corresponded with some targets before convincing them to open the malicious document attachment and inadvertently launch the payload. When opened, the malicious .doc file dropped several files in the hidden ProgramData folder: (1) MpSvc.dll, a malicious DLL with the same name as a legitimate Microsoft Defender Antivirus DLL, and (2) a copy of MsMpEng.exe the legitimate Microsoft Defender Antivirus executable.

The malicious document then added a scheduled task that launched the MsMpEng.exe copy and sideloaded the malicious MpSvc.dll. Because the latest versions of Microsoft Defender Antivirus are no longer susceptible to DLL sideloading, BISMUTH used an older copy to load the malicious DLL and establish a persistent command-and-control (C2) channel to the compromised device and consequently the network.

Using the newly established channel, the group dropped several files for the next stages of the attack, including a .7z archive, a copy of Word 2007, and another DLL, wwlib.dll. While it used the same name as a legitimate Microsoft Word DLL, wwlib.dll was a copy of KerrDown, a family of custom malware exclusive to BISMUTH. This file was subsequently sideloaded by the dropped copy of Word 2007—a technique used by BISMUTH extensively to load malicious code from a DLL file in the context of a legitimate process like winword.exe.

BISMUTH established another persistence method by dropping another copy of Word 2007 in a subfolder in ProgramData. The group then created a scheduled task that launched that copy in the same malicious manner every 60 minutes – further increasing their chances of going undetected and maintaining their presence.

Discovery

Once established as a scheduled task, the co-opted Word 2007 process dropped and loaded a scanning tool popular among attackers, NbtScan.exe. BISMUTH then immediately used the scanning tool to scan an IP address range within the organization. Following this network scan, the Word 2007 process launched a malicious script using a living-off-the-land-binary, rundll32.exe, resulting in a scan on a myriad of common ports, including 21, 22, 389, 139, and 1433. BISMUTH listed devices with open ports in a .csv file.

While network scanning was underway, the group performed other reconnaissance activities. They gathered information about domain and local administrators, checked whether users had local administrative privileges, and collected device information—aggregating results in a .csv for exfiltration. In addition, the group once again used MsMpEng.exe with the malicious sideloaded DLL to connect to another device that appears to have been designated by BISMUTH at some point during the attack as an internal C2 foothold and exfiltration staging device.

Continued lateral movement, discovery, and intel gathering

After a month of continual discovery on compromised devices, the group moved laterally to a server and copied over a malicious DLL that masqueraded as the system file mpr.dll and a copy of the Sysinternals DebugView tool. They dropped the tool onto different devices using SMB remote file copy, using file names related to popular Japanese video game characters and a seemingly random word. The actors then registered and launched malicious services multiple times, launching DebugView tool to connect to multiple Yahoo websites and confirm Internet connectivity, followed by a connection to their C2 infrastructure.

At this point, BISMUTH switched to running their attacks using PowerShell, quickly launching multiple script cmdlets. First, they dumped credentials from the Security Account Manager (SAM) database using the Empire PowerDump command and then quickly deleted PowerShell event logs to erase records generated by Script Block Logging. They then continued their discovery efforts using a PowerShell script that gathered user and group information and sent the gathered data to .csv files.

The script collected the following information about each user:

description, distinguishedname, lastlogontimestamp, logoncount, mail, name, primarygroupid, pwdlastset, samaccountname, userprincipalname, whenchanged, whencreated

And the following information about each domain group:

adspath, description, distinguishedname, groupType, instancetype, mail, member, memberof, name, objectsid, samaccountname,whenchanged, whencreated

Next, the group exported directory forest and domain organizational unit (OU) information. They then started connecting to dozens of devices using WMI. Following that, they collected credentials by dumping security logs under Event ID 680, possibly targeting logs related to NTLM fallbacks. Lastly, the group used the system tool Nltest.exe to gather domain trust info and pinged multiple servers they have identified by name during reconnaissance. Some of these servers appear to be database and file servers that could have contained high-value information for espionage objectives typically pursued by BISMUTH.

BISMUTH then installed a Cobalt Strike beacon. The group dropped a .rar file and extracted its contents—McOds.exe, which is a copy of the McAfee on-demand scanner, and a malicious DLL—into the SysWOW64 folder. The group then created a scheduled task that launched the copy of the McAfee on-demand scanner with SYSTEM privileges and sideloaded the malicious DLL. This persistence mechanism established a connection to their Cobalt Strike server infrastructure. To clean up evidence, they deleted the dropped McAfee binary.

In terms of targets for this campaign, there were some commonalities among targets located in Vietnam that Microsoft has assessed to be tied to their previous designation as state-owned enterprises (SOEs). The observed BISMUTH activity in Vietnam targeted organizations that included former SOEs previously operated by the government of Vietnam, entities that have acquired a significant portion of a former SOE, and entities that conduct transactions with a Vietnamese government agency. Although the group’s specific objectives for these recent attacks cannot be defined with high confidence, BISMUTH’s past activities have included operations in support of broader espionage goals.

Coin miner deployment and credential theft

As mentioned, BISMUTH deployed coin miners during these attacks. To do this, they first dropped a .dat file and loaded the file using rundll32.exe, which in turn downloaded a copy of the 7-zip tool named 7za.exe and a ZIP file. They then used 7-Zip to extract a Monero coin miner from the ZIP file and registered the miner as a service named after a common Virtual Machine process. Each coin miner they deployed had a unique wallet address that earned over a thousand U.S. dollars combined during the attacks.

After deploying coin miners as their distraction technique, BISMUTH then focused much of its efforts on credential theft. They registered multiple malicious services that used %comspec%—a relative reference to cmd.exe commonly used by attackers—to run the renamed DebugView tool while loading a malicious DLL. The group used DebugView and the malicious DLL in a fairly unexpected fashion to launch Base64-encoded Mimikatz commands using one of several Windows processes: makecab.exe, systray.exe, w32tm.exe, bootcfg.exe, diskperf.exe, esentutl.exe, and typeperf.exe.

They ran the following Mimikatz commands that require SYSTEM or Debug privileges:

  • sekurlsa::logonpasswords full–lists all account and user password hashes, typically user and computer credentials for recently logged on users
  • lsadump::lsa /inject—injects LSASS to retrieve credentials and request the LSA Server to grab credentials from the Security Account Manager (SAM) database and Active Directory (AD)

After running these commands, the co-opted DebugView tool connected to multiple attacker-controlled domains, likely to exfiltrate stolen credentials.

As the affected organizations worked to evict BISMUTH from their networks, Microsoft security researchers saw continued activity involving lateral movement to other devices, credential dumping, and planting of multiple persistence methods. This highlights the complexity of responding to a full-blown intrusion and the significance of taking quick action to resolve alerts that flag initial stages of an attack.

Building organizational resilience against attacks that blend in

BISMUTH attacks put strong emphasis on hiding in plain sight by blending in with normal network activity or common threats that attackers anticipate will get low-priority attention. The combination of social engineering and use of legitimate applications to sideload malicious DLLs entail multiple layers of protection focused on stopping threats at the earliest possible stage and mitigating the progression of attacks if they manage to slip through. Here are mitigation recommendations that organizations can implement to limit exposure:

Limit the attack surface that attackers can leverage for initial access:

  • Educate end users about protecting personal and business information in social media, filtering unsolicited communication, identifying lures in spear-phishing email, and reporting of reconnaissance attempts and other suspicious activity.
  • Configure Office 365 email filtering settings to ensure blocking of phishing & spoofed emails, spam, and emails with malware. Set Office 365 to recheck links on click and delete sent mail to benefit from newly acquired threat intelligence.
  • Turn on attack surface reduction rules, including rules that can block advanced macro activity, executable content, process creation, and process injection initiated by Office applications.
  • Disallow macros or allow only macros from trusted locations. See the latest security baselines for Office and Office 365.
  • Check perimeter firewall and proxy to restrict servers from making arbitrary connections to the internet to browse or download files. Such restrictions help inhibit malware downloads and command-and-control activity.

Build credential hygiene to reduce risk during discovery stage:

  • Enforce strong, randomized local administrator passwords. Use tools like LAPS.
  • Practice the principle of least-privilege and maintain credential hygiene. Avoid the use of domain-wide, admin-level service accounts.
  • Require multi-factor authentication through Windows Hello.

Stop attack sprawl and contain attacker movement:

  • Turn on cloud-delivered protection and automatic sample submission on Microsoft Defender Antivirus. These capabilities use artificial intelligence and machine learning to quickly identify and stop new and unknown threats.
  • Turn on tamper protection features to prevent attackers from stopping security services.
  • Monitor for clearing of event logs. Windows generates security event ID 1102 when this occurs.
  • Determine where highly privileged accounts are logging on and exposing credentials. Monitor and investigate logon events (event ID 4624) for logon type attributes. Highly privileged accounts should not be present on workstations.
  • Utilize the Microsoft Defender Firewall, intrusion prevention devices, and your network firewall to prevent RPC and SMB communication among endpoints whenever possible. This limits lateral movement as well as other attack activities.

To better defend organizations against attacks that do everything to blend in once they gain access to a network, organizations can build defenses for preventing and blocking attacks at the initial access stage. Microsoft Defender for Office 365 provides defense capabilities that protect organizations from threats like credential phishing, business email compromise, and cyberattacks that begin with spear-phishing emails. Safe attachments and Safe links provide real-time protection using a combination of detonation, automated analysis, and machine learning, which are especially useful for highly targeted, specially crafted emails. Campaign views show the complete picture of email campaigns, including timelines, sending patterns, impact to the organization, and details like IP addresses, senders, URLs.

The broader Microsoft 365 Defender presents cross-domain threat intelligence and actionable information in consolidated incidents view, empowering security operations teams to comprehensively respond to attacks. For critical threats like BISMUTH campaigns, Microsoft researchers publish threat analytics reports that contain technical details, detection info, and mitigation status. Investigation tools like advanced hunting allow security teams to perform additional inspection of the environment for related or similar threats. Threat and vulnerability management data show mitigation recommendations, including enabling relevant attack surface reduction rules, that organizations can take to reduce risks.

These industry-leading capabilities in Microsoft 365 Defender are backed by Microsoft’s network of researchers and security experts who monitor the threat landscape and track threat actors like BISMUTH. Through Microsoft 365 Defender, we transform threat intelligence into protections and rich investigation tools that organizations can use to build organizational resilience. Learn how you can stop attacks through automated, cross-domain security and built-in AI with Microsoft Defender 365.

 

Justin Carroll and Emily Hacker, Microsoft 365 Defender Threat Intelligence Team

with Microsoft Threat Intelligence Center (MSTIC)

 

MITRE ATT&CK techniques observed

Initial access

Execution

Persistence

Privilege escalation

Defense evasion

Credential access

Discovery

Collection

Data exfiltration

The post Threat actor leverages coin miner techniques to stay under the radar – here’s how to spot them appeared first on Microsoft Security.