Suspicious FL Studio Executable Side-Loading flengine DLL From Non-Standard Path

PremiumReviewedSigma · High · v1
Product
windows
Category
image_load
Author
HuntRule
Published
2026-07-31
Updated
2026-08-28

ATT&CK techniques

Execution → Defense Evasion
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule detects the legitimate FL Studio binary fl.exe loading flengine.dll from a directory outside its normal installation path which is the DLL side-loading technique used to launch the BITSLOTH backdoor. Adversaries abuse this trusted signed executable to proxy execution of malicious code and evade defenses.

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Suspicious FL Studio Executable Side-Loading flengine DLL From Non-Standard Path
Pivot detection · T1574.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.