Tuesday, April 22, 2025

Most often encountered malware and abused software program – Sophos Information

This appendix to our Annual Menace Report offers extra statistics on incident knowledge and telemetry detailing the instruments utilized by cybercriminals focusing on small and midsized companies (SMBs). For a broader take a look at the risk panorama going through SMBs, see our fundamental report.

Appendix Contents:

Most often-encountered malware sorts

Small and midsized companies face an unlimited set of threats to knowledge—a few of which can be precursors to ransomware assaults or could end in different breaches of delicate data. Ransomware dominates the malware noticed in Sophos MDR and Sophos Incident Response instances from 2024, with the highest 10 accounting for over 25% of all incidents MDR and IR tracked over the yr. However they weren’t the complete story, and almost 60% of MDR incidents concerned threats not involving ransomware.

 

 Other12.79% Miner 0.89% Ransomware 1.18% Web/Browser Hijack 3.60% Attack tool/Exploit/EDR Killer 7.95% RAT/Backdoor 15.52% Stealer/Spyware 18.63% Loader/Downloader/Dropper 39.74% 9.13% of all malware was malware-as-a-service

Determine 13: Probably the most generally seen classes of malware detection seen in 2024, primarily based on buyer detection stories

Qilin (ransomware)1.05% Blacksuit (ransomware) 1.23% Faust (ransomware) 1.23% Crytox (ransomware) 1.41% Playcrypt (ransomware) 1.58% Black Basta (ransomware) 1.93% RansomHub (ransomware) 2.28% Gootloader (malware loader/dropper) 2.64% ChromeLoader (malware loader/dropper) 3.51% Fog (ransomware) 3.51% LockBit (ransomware) 4.39% Lumma Stealer (information stealer) 4.57% Akira (ransomware) 4.92% Cobalt Strike (C2 tool) 8.08% Web shell (C2) 9.84%
Determine 14: Prime 15 malware and assault instruments encountered in MDR and IR incidents

Command-and-control instruments, malware loaders, distant administration instruments, and information-stealing malware make up the vast majority of the malicious software program seen focusing on small companies (other than ransomware). And these instruments, not all of that are technically malware, are used as a part of the supply of ransomware and different cybercriminal assaults.

Solely one of many high 10 instruments and malware seen in Sophos MDR and IR incidents doesn’t fall into this class: XMRig. It’s a cryptocurrency-mining malware typically used to passively generate income earlier than entry is offered or in any other case exploited by a ransomware actor.

Determine 20: Prime information-stealing malware detections reported by endpoint safety prospects
ExMatter (data exfiltration)0.56% Backstab (EDR killer) 0.56% Parcel RAT 0.56% DataGrabber (data exfiltration) 0.56% AsyncRAT 0.56% Sliver attack tool 0.56% Pikabot backdoor 0.56% Brute Ratel C4 0.56% Metasploit exploit framework 1.11% Grixba network scanning tool 1.11% SystemBC proxy/RAT 1.67% XMRIG miner malware 2.22% Web shell 7.22% Cobalt Strike attack tool 10.56%
Determine 16: Prime non-ransomware malware and instruments seen in Sophos MDR and Sophos Incident Response instances particularly in ransomware-related incidents

 

Twin-use instruments

One development that continues from earlier years is the intensive use of usually obtainable industrial, freeware, and open-source software program by cybercriminals to conduct ransomware assaults and different malicious exercise. Sophos MDR refers to those as “dual-use instruments,” as they might be current on networks for respectable causes, however are often utilized by cybercriminals for malicious functions.

Twin-use instruments are totally different from “living-off-the-land binaries” (LOLBins) in that they’re full functions deployed and used as supposed by malicious actors, fairly than working system-supplied elements and scripting engines. A few of the instruments that fall into “twin use” are particularly safety testing-oriented and supposed for crimson groups—Impacket and Mimikatz are open-source instruments that have been constructed particularly for safety researchers. Others akin to SoftPerfect Community Scanner and Superior IP Scanner are supposed as instruments for community directors, however can be utilized by cybercriminals for discovery of networked gadgets and open community ports.

Advanced Port Scanner (network discovery)4.92% FileZilla (file exfiltration) 5.10% Rclone (file exfiltration) 7.38% 7-Zip (file archiving/encryption) 7.38% PuTTy (remote command execution) 7.73% ScreenConnect (remote desktop access) 9.14% WinRAR (file archiving/encryption) 9.31% Sophos Uninstall (security tool removal) 9.49% Advanced IP Scanner (network discovery) 10.72% Mimikatz (credential dumping) 11.60% RDPclip (remote/local shared clipboard) 16.70% Impacket (network protocol exploitation) 17.05% AnyDesk (remote desktop access) 17.40% PsExec (remote command execution) 18.28% SoftPerfect Network Scanner (network discovery) 19.51%

Determine 17: Prime 15 “twin use” instruments seen in Sophos MDR and Sophos Incident Response incidents, by frequency

Determine 18: Prime 9 “twin use” assault instruments in Sophos endpoint detections 

Business distant entry instruments are collectively essentially the most often used dual-use instruments encountered in MDR and IR incidents:

TypeFrequency LevelRMM (remote machine management) 0.70% RemCom (remote command execution) 0.70% MobaXterm (remote shell) 0.88% VNC (remote desktop) 1.58% NetSupport (remote machine management) 1.76% Cloudflared (Cloudflare network tunneling client) 1.76% Ngrok (web application tunneling) 2.11% WinRM (remote machine management) 2.28% Splashtop (remote desktop) 2.99% TeamViewer (remote desktop) 3.16% Atera (remote machine management) 3.51% OpenSSH (remote shell) 4.04% PuTTy (remote shell) 7.73% ScreenConnect (remote desktop) 9.14% AnyDesk (remote desktop) 17.40% PSExec (remote command execution) 18.28%
Determine 19: Prime 15 dual-use instruments seen in Sophos MDR and Incident Response incidents, by frequency

With industrial distant entry instruments, the attackers normally abuse trial account licenses or use pirated licenses for the variations they deploy to focused machines. In lots of instances, that is finished after preliminary exploitation by means of malware droppers, internet shells, or different command-and-control instruments. In others, it’s pushed by means of social engineering—getting a focused particular person to obtain and set up the device themselves, as we have now seen in latest Groups “vishing” assaults.

Use of respectable distant machine administration instruments, significantly by ransomware actors, has been rising, although distant desktop entry instruments AnyDesk and ScreenConnect stay essentially the most often used industrial IT help instruments seen in Sophos MDR and IR incidents. And the commonest device stays PSExec, a Microsoft “light-weight Telnet replacement” used to remotely execute instructions and create command shell periods.

Sophos prospects can prohibit their utilization by means of Sophos Central utilizing utility management insurance policies—and may prohibit any instruments that aren’t getting used for respectable IT help.

Assault instruments

Cobalt Strike, Sliver, Metasploit, and Brute Ratel are penetration testing instruments, and never malware within the authorized sense. However they’re often used to ship malware and for command and management of malware assaults. Having a well-documented, commercially supported post-exploitation device like these is a significant plus for cybercriminals who would in any other case need to construct their very own instruments to increase their footprint inside a focused group.

Cobalt Strike stays essentially the most closely used of those assault instruments, current in eight % of all incidents and almost 11 % of ransomware-related incidents. It is a important decline from 2023, when Cobalt Strike was the third most often seen industrial device utilized in MDR incidents, rating solely behind the AnyDesk and PSExec distant entry instruments. Sliver and Metasploit-based instruments, which can be found as open-source, are seen even much less often, and Brute Ratel utilization by cybercriminals stays extraordinarily uncommon.

Data stealers

Determine 20: Prime information-stealing malware detections reported by endpoint safety prospects

 

Data-stealing malware is commonly step one within the entry dealer’s playbook, offering passwords, cookies, and different knowledge that can be utilized for monetary fraud, enterprise electronic mail compromise, and ransomware assaults, amongst different schemes.

Lumma Stealer, offered by means of Russian-speaking boards as a Malware-as-a-Service (MaaS), was essentially the most often encountered data stealer in MDR incidents, and second in general endpoint detection stories. A serious Lumma Stealer marketing campaign starting in October made it essentially the most reported stealer for the final quarter of 2024, far surpassing final yr’s MaaS stealer chief RaccoonStealer (which launched  a brand new model in 2024 after its infrastructure was disrupted) and by yr’s finish eclipsing Strela Stealer (which was rising within the ranks in 2023; it peaked early in 2024, however trailed off within the second half of the yr). No MDR incidents tracked in 2024 concerned Strela Stealer.

A chart showing a histogram of Lumma Stealer detections, with a majority of detections occurring in October and November of 2024.

Determine 21: Lumma Stealer exercise in 2024 as noticed in buyer endpoint detections

A histogram showing a peak of Lumma Stealer events in November
Determine 22: Lumma Stealer associated MDR incidents in 2024

 

A histogram showing spikes of Strela Stealer detections in February, March and July of 2024.
Determine 23: Strela Stealer exercise in 2024 as noticed in buyer endpoint detections

First tracked in August 2022, Lumma Stealer is believed to be a successor of  Mars Stealer, one other data stealer purportedly of Russian origin. This stealer primarily targets cryptocurrency wallets, browser session cookies, browser two-factor authentication extensions, saved File Switch Protocol server addresses and credentials, and different person and system knowledge.

Like another data stealers (akin to Raccoon Stealer), Lumma Stealer may also be used to ship extra malware—both by launching executables or PowerShell scripts, or by loading malicious DLLs from its personal course of. Sometimes, Lumma Stealer is delivered from a  compromised web site (typically a pretend CAPTCHA internet web page) as a obtain that victims are dropped at through malvertising.

Lumma Stealer is mostly related to broader cybercriminal exercise. One other MaaS stealer offered on Russian-language boards, StealC, was seen with a a lot larger correlation to ransomware incidents. Launched in January 2023, it has been labeled by researchers as a RaccoonStealer and Vidar copycat.

Of regional notice is Mispadu Stealer, which continues to focus on Latin America (and Mexico specifically). Within the second quarter of 2024, it was the second-most detected stealer, coming in simply behind Strela Stealer, with 74% of these detections coming from Mexico.  It has been seen utilizing malicious internet and search promoting, notably posing as internet adverts for McDonald’s.

Prime ransomware threats

Stealc (information stealer)0.35% AsyncRAT (RAT with infostealer features) 0.53% More_eggs (RAT that can carry infostealer payload) 0.53% Brute Ratel C4 (red team C2 tool) 0.53% Metasploit (red team command and control tool) 0.70% Remcos (RAT) 0.70% FakeBat /EugenLoader (malware loader) 0.70% Sliver (red team C2 tool) 0.88% XMRIG (cryptocurrency miner) 1.05% SystemBC (proxy and RAT) 1.05% Gootloader (malware loader) 2.64% ChromeLoader (browser malware loader) 3.51% Lumma Stealer (information stealer) 4.57% Cobalt Strike (red team C2 tool with information stealing modules) 8.08% Web shell (malware deployment, command and control) 9.84%
Determine 24: Most often detected ransomware households throughout all Sophos endpoint prospects

 

Cicada33011.64% Mimic 1.64% Hunters International 2.19% INC Ransomware 2.19% 8Base 2.73% Qilin 3.28% Blacksuit 3.83% Faust 3.83% Crytox 4.37% Playcrypt 4.92% Black Basta 6.01% RansomHub 7.10% Fog 10.93% LockBit 13.66% Akira 15.30%
Determine 25: The highest ransomware households encountered in MDR and Incident Response incidents

LockBit, form of

Probably the most-detected ransomware household in 2024 was LockBit, however not due to the ransomware group that spawned it. In February 2024, US and UK legislation enforcement claimed to have disrupted the LockBit group by seizing the ransomware-as-a-service group’s servers, arresting two of its members, and charging one other in an indictment. Within the wake of this disruption, quite a few variants primarily based on the leaked LockBit 3.0 code grew to become lively within the wild, leading to a spike of LockBit detections in early 2024. Nonetheless, by March, detections trailed off considerably with a slight rebound in April and early Might (although the LockBit gang might not be gone perpetually).

The teams utilizing LockBit 3.0 often used EDR killers and different malware and strategies to aim to disable endpoint safety. Their preliminary entry was typically by means of VPN accounts that had been compromised (in some instances resulting from vulnerabilities within the VPN gadgets themselves), or by means of the abuse of credentials harvested from unmanaged gadgets to realize distant entry.

A histogram of Lockbit variant ransomware detections with a spike in late February 2024.
Determine 26: LockBit variant detections per day, 2024

Akira and Fog

By way of precise incidents, the Akira ransomware-as-a-service led the pack in 2024, finally stepping in to fill the void left by LockBit. Initially seen in 2022, Akira assaults ramped up in late 2023. The group and its associates have been steadily lively all through 2024, spiking in August when Akira accounted for 17% of the ransomware detections reported by Sophos prospects—doubling from its place within the first two quarters of the yr. By yr’s finish, it nonetheless accounted for 9% of ransomware detection stories.

Notably, Sophos noticed associates tied to Akira additionally deploying different ransomware variants, together with Fog, Frag and Megazord. These attackers (akin to these in STAC5881) sometimes centered on exploiting VPNs for preliminary entry. Sometimes, Akira’s targets had VPNs with no multifactor authentication, or had misconfigured VPN gateways that allowed the attackers to realize entry with stolen credentials or brute power assaults.

Whereas Akira stays lively, Fog ransomware has often been used as a alternative by associates beforehand related to Akira, which accounts for its place in third among the many high 15 ransomware households encountered in MDR and IR incidents.

RansomHub

RansomHub was one other rising chief in ransomware incidents in 2024. Whereas tied for sixth in general detections, RansomHub was the fourth most noticed ransomware household in precise MDR and IR incidents.

Between February and August 2024, in response to a Cybersecurity and Infrastructure Safety Company #StopRansomware advisory, RansomHub had “encrypted and exfiltrated knowledge from a minimum of 210 victims.” The vast majority of Sophos MDR and IR instances involving RansomHub got here within the second half of the yr, mounting in numbers in November.

Most RansomHub assaults concerned abuse of RDP along with different respectable distant desktop instruments, together with AnyDesk. Preliminary entry in some reported instances got here from leveraging the seven-year-old Home windows SMB Distant Code Execution Vulnerability (CVE-2017-1444), although this was not noticed within the Sophos MDR and IR instances represented in our knowledge. Preliminary entry vectors Sophos X-Ops noticed in RansomHub instances included abuse of externally going through Microsoft SQL Servers for command execution, abuse of open RDP and Distant Desktop Internet entry, and compromise of unmanaged gadgets.

 

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