Suspicious wscript Executing Single-Letter VBS Loader

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.005Visual Basic
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects wscript or cscript running one of the single-letter helper scripts a.vbs b.vbs or m.vbs dropped by the malicious Cursor extension chain. These VBScripts stage the ScreenConnect installer and downstream Quasar and PureLogs payloads. The specific script names invoked by the Windows Script Host are a reliable campaign artifact.

Reporting behind it

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Suspicious wscript Executing Single-Letter VBS Loader

Pivot detection · T1059.005 · 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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