Detection Insight: Suspicious .accdr Dropper Activity (Possible Bitter Tradecraft) A recent our...

Summary

Security researchers identified a cluster of malicious Microsoft Access Runtime (.accdr) files functioning as droppers, potentially linked to Bitter threat actor tradecraft. The files exhibited extremely low antivirus detection rates (0/62), suggesting sophisticated evasion techniques. This indicates an active campaign leveraging legitimate Office file formats for payload delivery.

Indicators of Compromise

• malware — .accdr dropper
• mitre_attack — T1566.001
• mitre_attack — T1140

Entities