Detectionhightest

Suspicious Serv-U Process Pattern

Detects a suspicious process pattern which could be a sign of an exploited Serv-U service

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Florian Roth (Nextron Systems)Created Wed Jul 14Updated Thu Jul 1458f4ea09-0fc2-4520-ba18-b85c540b0eafwindows
Log Source
WindowsProcess Creation
ProductWindows← raw: windows
CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic
Detection Logic1 selector
detection:
    selection:
        ParentImage|endswith: '\Serv-U.exe'
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\wscript.exe'
            - '\cscript.exe'
            - '\sh.exe'
            - '\bash.exe'
            - '\schtasks.exe'
            - '\regsvr32.exe'
            - '\wmic.exe'  # https://app.any.run/tasks/c903e9c8-0350-440c-8688-3881b556b8e0/
            - '\mshta.exe'
            - '\rundll32.exe'
            - '\msiexec.exe'
            - '\forfiles.exe'
            - '\scriptrunner.exe'
    condition: selection
False Positives

Legitimate uses in which users or programs use the SSH service of Serv-U for remote command execution

MITRE ATT&CK
Rule Metadata
Rule ID
58f4ea09-0fc2-4520-ba18-b85c540b0eaf
Status
test
Level
high
Type
Detection
Created
Wed Jul 14
Modified
Thu Jul 14
Path
rules/windows/process_creation/proc_creation_win_servu_susp_child_process.yml
Raw Tags
attack.credential-accessattack.t1555cve.2021-35211
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