Sigma rule: Process Access via TrolleyExpress Exclusion

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-f917369af2d5, updated 2022-05-13T00:00:00.000Z.

Rule

Title
Process Access via TrolleyExpress Exclusion
Status
test
Level
high
Author
Florian Roth (Nextron Systems)
Date
2022-02-10
Modified
2022-05-13
File
rules/windows/process_creation/proc_creation_win_citrix_trolleyexpress_procdump.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a possible process memory dump that uses the white-listed Citrix TrolleyExpress.exe filename as a way to dump the lsass process memory

Log source

product
windows
category
process_creation

Detection

selection:
    CommandLine|contains:
  # We assume that the lsass.exe process has a process ID that's between 700 and 999 and the dumper uses just the PID as parameter
        - '\TrolleyExpress 7'
        - '\TrolleyExpress 8'
        - '\TrolleyExpress 9'
        - '\TrolleyExpress.exe 7'
        - '\TrolleyExpress.exe 8'
        - '\TrolleyExpress.exe 9'
  # Common dumpers
        - '\TrolleyExpress.exe -ma '
renamed:
    Image|endswith: '\TrolleyExpress.exe'
filter_renamed:
    OriginalFileName|contains: 'CtxInstall'
filter_empty:
    OriginalFileName: null
condition: selection or ( renamed and not 1 of filter* )

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.stealth
  • attack.t1218.011
  • attack.credential-access
  • attack.t1003.001

MITRE ATT&CK ids this rule names

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_citrix_trolleyexpress_procdump.yml

Sources and licences

  • SigmaHQ

    "Process Access via TrolleyExpress Exclusion" by Florian Roth (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_citrix_trolleyexpress_procdump.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Process Access via TrolleyExpress Exclusion",
entity page, dataset version ref-f917369af2d5, updated 2022-05-13T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/4c0aaedc-154c-4427-ada0-d80ef9c9deb6 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 4c0aaedc-154c-4427-ada0-d80ef9c9deb6, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.