Ongoing SonicWall Secure Mobile Access (SMA) Exploitation Campaign using the OVERSTEP Backdoor


Google Threat Intelligence Group (GTIG) has identified an ongoing campaign by a suspected financially-motivated threat actor we track as UNC6148, targeting fully patched end-of-life SonicWall Secure Mobile Access (SMA) 100 series appliances.

GTIG assesses with high confidence that UNC6148 is leveraging credentials and one-time password (OTP) seeds stolen during previous intrusions, allowing them to regain access even after organizations have applied security updates. Evidence for the initial infection vector was limited, as the actor’s malware is designed to selectively remove log entries, hindering forensic investigation; however, it is likely this was through the exploitation of known vulnerabilities.

Read more…
Source: Mandiant/GTG


Sign up for the Cyber Security Review Newsletter
The latest cyber security news and insights delivered right to your inbox


Related:

  • Critical Buffer Overflow in Palo Alto Networks PAN-OS User-ID Authentication Portal (CVE-2026-0300)

    May 6, 2026

    On May 6, 2026, Palo Alto Networks published a security advisory for CVE-2026-0300, a critical unauthenticated buffer overflow vulnerability affecting PAN-OS PA-Series and VM-Series firewall appliances. Prisma Access, Cloud NGFW, and Panorama appliances are not affected by this vulnerability. The vulnerability carries a CVSSv4 score of 9.3 and has been confirmed as exploited in the wild ...

  • Update WhatsApp now: Two new flaws could expose you to malicious files

    May 5, 2026

    Meta has published a new security advisory for messaging app WhatsApp, announcing patches for two vulnerabilities. WhatsApp has fixed two security flaws that could be abused to interfere with how media and attachments are handled on your device. There is no evidence that either bug has been exploited in the wild. These bugs don’t automatically infect ...

  • DAEMON Tools software compromised with a malicious payload

    May 5, 2026

    In early May 2026, Kaspersky researchers identified installers of the DAEMON Tools software, used for mounting disk images, to be compromised with a malicious payload. These installers are distributed from the legitimate website of DAEMON Tools and are signed with digital certificates belonging to DAEMON Tools developers. Kaspersky analysis revealed that the software installers have been ...

  • Trellix confirms data breach after hack of ‘a portion’ of its source code

    May 5, 2026

    Cybersecurity giant Trellix has confirmed suffering a cyberattack in which threat actors accessed parts of its source code. In a brief announcement published on its website, Trellix said it had identified “unauthorized access to a portion of source code repository”. As soon as it spotted the intrusion, the company brought in third-party security experts to ...

  • Quasar Linux (QLNX) – Inside a Full-Featured Linux RAT

    May 4, 2026

    In previous research, Trend Micro have demonstrated how AI can be used to improve detection accuracy when new malware families emerge, particularly those that reuse or share code from open-source repositories. In this blog entry, Trends Micro researchers present another compelling finding from the same approach. Trend Micro platform recently flagged an unusual Linux implant with ...

  • Thousands of Facebook accounts stolen by phishing emails sent through Google

    May 4, 2026

    Researchers have uncovered a long-running phishing operation that abuses trusted Google services to hijack tens of thousands of Facebook accounts. The compromised Facebook accounts are mainly business and advertiser profiles, which criminals can monetize after gaining access and control. The attackers found a way to send phishing emails that come “through Google,” making them look legitimate ...