Suspicious S3 Access from Desktop File Transfer Clients by Bling Libra

ATT&CK techniques

Initial Access → Discovery

Recon
Resource Dev
Initial Access
- T1078.004Cloud Accounts
Execution
Persistence
- T1078.004Cloud Accounts
Priv Esc
- T1078.004Cloud Accounts
Defense Evasion
- T1078.004Cloud Accounts
Cred Access
Discovery
- T1526Cloud Service Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects AWS S3 API activity originating from desktop file transfer clients identified by S3 Browser and WinSCP user agents, tooling the Bling Libra group behind ShinyHunters used to enumerate and manipulate buckets with stolen credentials. Interactive client access to S3 is unusual for automated workloads and signals hands-on abuse. Detecting this exposes credentialed data access ahead of extortion.

Reporting behind it

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Suspicious S3 Access from Desktop File Transfer Clients by Bling Libra

Pivot detection · T1078.004 · 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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