Detectionhightest

Uncommon Network Connection Initiated By Certutil.EXE

Detects a network connection initiated by the certutil.exe utility. Attackers can abuse the utility in order to download malware or additional payloads.

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Launch
François Hubaut, Florian Roth (Nextron Systems)Created Fri Sep 02Updated Fri May 310dba975d-a193-4ed1-a067-424df57570d1windows
Log Source
WindowsNetwork Connection
ProductWindows← raw: windows
CategoryNetwork Connection← raw: network_connection

Events for outbound and inbound network connections including DNS resolution.

Detection Logic
Detection Logic1 selector
detection:
    selection:
        Image|endswith: '\certutil.exe'
        Initiated: 'true'
        DestinationPort:
            - 80
            - 135
            - 443
            - 445
    condition: selection
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

Rule Metadata
Rule ID
0dba975d-a193-4ed1-a067-424df57570d1
Status
test
Level
high
Type
Detection
Created
Fri Sep 02
Modified
Fri May 31
Path
rules/windows/network_connection/net_connection_win_certutil_initiated_connection.yml
Raw Tags
attack.command-and-controlattack.t1105
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