Sunturai
Back to results
InformationalSplunk security contentMichael Haag +1

Windows Rundll32 Execution With Log.DLL

Identifies the execution of rundll32 with a command line argument of "log.dll", as used in the Lotus Blossom Chrysalis backdoor campaign. Attackers placed a malicious "log.dll" in "%AppData%\Bluetooth" and invoked it…

Description

Identifies the execution of rundll32 with a command line argument of "log.dll", as used in the Lotus Blossom Chrysalis backdoor campaign. Attackers placed a malicious "log.dll" in "%AppData%\Bluetooth" and invoked it via rundll32.exe "log.dll,LogInit" to decrypt and execute ShellCode. The legitimate Bitdefender Submission Wizard (BDSubmit.exe, bdsw.exe) also uses log.dll and is vulnerable to DLL sideloading.

Detection logic

Detection requirements

Platform
LinuxmacOSWindows

The rule states no platform. This is derived from the ATT&CK technique it maps to.

Log source category
crowdstrike_processrollup2sysmon_eventid_1windows_event_log_security_4688

Known benign triggers

  • Legitimate use of rundll32 to load log.dll from trusted locations may trigger this. Allowlist known paths or parent processes as needed.

Detections can measure how the public catalogue is used — which detections people look for, and which pages bring them here. It sets a cookie that recognises this browser for 180 days. It is never linked to an account and never follows you to other sites. Privacy notice