Suspicious Weaver Ant In-Memory Web Shell Marker in Web Request (via webserver)

ATT&CK techniques

Persistence → C2

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1505.003Web Shell
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1071.001Web Protocols
Exfiltration
Impact

What it detects

This rule detects web requests containing base64 encoded markers used by the Weaver Ant in-memory web shell to invoke its evaluation handler. The tokens decode to the evaluation handler and invoke keywords that the web shell uses to execute compressed payloads without writing to disk. These strings are not expected in legitimate application traffic.

Reporting behind it

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Suspicious Weaver Ant In-Memory Web Shell Marker in Web Request (via webserver)

Pivot detection · T1071.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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