MALWARE FAMILY
BACKBEND
Internal ID: win.backbend
1
aliases
Last seen:Mar 17, 2026
Intelligence Profile
FireEye describes BACKBEND as a secondary downloader used as a backup mechanism in the case the primary backdoor is removed. When executed, BACKBEND checks for the presence of the mutexes MicrosoftZj or MicrosoftZjBak (both associated with BACKSPACE variants). If either of the mutexes exist, the malware exits.
Threat Analysis
BACKBEND is a malware family tracked by threat intelligence researchers and catalogued in the Malpedia dataset. It represents a distinct malicious software lineage with identifiable code characteristics, behaviors, and victimology.
External References
Quick Facts
TypeMalware Family
Aliases1
Also Known As
win.backbend
Research Links
Data sourced from Malpedia, Ransomware.live, RansomLook, and CTIWATCH OSINT collection. Actor attribution is based on available intelligence and may be incomplete.