Gamshen
Gamshen is a malicious Microsoft Internet Information Services (IIS) module associated with the GhostRedirector threat actor and used to facilitate SEO fraud. Public reporting cited here states GhostRedirector compromised at least 65 Windows servers and deployed Gamshen alongside a passive C++ backdoor named Rungan. Reported victim geography primarily included Brazil, Thailand, and Vietnam. ESET assessed that Gamshen was used to provide SEO-fraud-as-a-service by manipulating search engine results, including redirect-oriented abuse tied to gambling-related outcomes. The malware targets Windows IIS servers and operates as an IIS module rather than a standalone payload. The content does not provide specific file hashes, domains, or other concrete IOC values for Gamshen beyond its name and association with GhostRedirector/Rungan.
Hunt this family in your stack
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Groups observed using it
1 distinct threat actor attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
... and a native Internet Information Services (IIS) module codenamed Gamshen.
Techniques & procedures
2 distinct techniques documented for this family, organized by ATT&CK tactic.
Initial Access
1 technique"Once a vulnerable IIS server is found – either via security vulnerability or weak settings in the web server's file upload feature – the threat actor uses the foothold to upload web shells..."
Persistence
1 technique"BadIIS ... Plants Web Shells"; "GhostRedirector ... native Internet Information Services (IIS) module"
Recent activity
4 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Native IIS module used in GhostRedirector compromises; likely for traffic manipulation/redirect behavior (implied by context); no further details in excerpt.
Named tooling/artifact associated with GhostRedirector activity; used as a differentiator from UAT-8099/WEBJACK-style activity.
Malicious IIS module used to facilitate SEO fraud; described as functionally similar to BadIIS in that it conditionally triggers SEO manipulation based on Google-originated requests (Googlebot User-Agent).
Native IIS module used to provide SEO fraud-as-a-service by manipulating search engine results to boost rankings for a configured target website.
The version that knows your environment.
Match every observed IP, domain, and hash against your live telemetry.
Named campaigns wielding this family, with evidence pinned to each claim.
CVEs this family uses for access and lateral movement.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.