Malware

TunnesshClient

TunnesshClient is a PyInstaller backdoor observed as an additional payload in a large-scale malware distribution campaign that used more than 100 public GitHub repositories to spread the BoryptGrab information stealer via ZIP archives masquerading as legitimate software tools, utilities, and game cheats. In the reported infection chains, attackers used SEO-stuffed GitHub README files, fake download pages, DLL sideloading, VBS/PowerShell downloaders, and .NET loaders to deliver BoryptGrab and secondary payloads including TunnesshClient, Vidar variants, and the HeaconLoad Golang downloader. TunnesshClient establishes a reverse SSH tunnel to communicate with attackers and can act as a SOCKS5 proxy, providing remote access, file movement, and proxying through the infected host. It was specifically described as creating a reverse SSH tunnel enabling remote command execution, file movement, and proxying. The campaign infrastructure and Russian-language artifacts cited in the reporting suggest the operators may be of Russian origin. The malware was associated with infections targeting Windows systems through trojanized ZIP-delivered software and cheat lures hosted via GitHub-related infrastructure.

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MITRE ATT&CK

Techniques & procedures

2 distinct techniques documented for this family, organized by ATT&CK tactic.

Command and Control

2 techniques

T1105Ingress Tool TransferEvidence1

The launcher downloads the BoryptGrab information stealer and may also retrieve other payloads, including Vidar variants... and a Golang downloader named HeaconLoad.

T1572Protocol TunnelingEvidence1

...TunnesshClient, which creates a reverse SSH tunnel to communicate with attackers... establishes a reverse SSH tunnel, allowing attackers to run commands, move files, and use the infected system as a proxy.

ACTIVITY FEED

Recent activity

2 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

2 SOURCESView more in app

the hacker newsNews

Mar 12, 2026

ThreatsDay Bulletin: OAuth Trap, EDR Killer, Signal Phishing, Zombie ZIP, AI Platform Hack & More

Backdoor enabling reverse SSH tunneling and SOCKS5 proxying for attacker communications and pivoting.

security affairsNews

Mar 8, 2026

Massive GitHub malware operation spreads BoryptGrab stealer

PyInstaller-based backdoor that establishes a reverse SSH tunnel, enabling remote command execution, file movement, and use of the victim host as a proxy.

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IOC matching

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Threat actor attribution

Named campaigns wielding this family, with evidence pinned to each claim.

Exploited vulnerabilities

CVEs this family uses for access and lateral movement.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

MITRE ATT&CK mapping2

Every documented technique, ranked by evidence weight.

Researcher chatter

Reddit, Mastodon, and CTI community discussion around this family.