Emerging Threathightest

Potential Pikabot C2 Activity

Detects the execution of rundll32 that leads to an external network connection. The malware Pikabot has been seen to use this technique to initiate C2-communication through hard-coded Windows binaries.

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Launch
Andreas Braathen (mnemonic.io)Created Fri Oct 27Updated Fri Jan 26cae6cee6-0244-44d2-84ed-e65f548eb7dc2023
Emerging Threat
Active Threat

Developed to detect an active or emerging threat. Prioritize investigation of any alerts and correlate with threat intelligence.

Log Source
WindowsNetwork Connection
ProductWindows← raw: windows
CategoryNetwork Connection← raw: network_connection

Events for outbound and inbound network connections including DNS resolution.

Definition

Requirements: By default the network_connection type event might not contain the ParentImage. Make sure you collect such fields in order to use this rule

Detection Logic
Detection Logic1 selector
detection:
    selection:
        ParentImage|endswith: '\rundll32.exe'
        Image|endswith:
            # Note: Only add processes seen used by Pikabot to avoid collision with other strains of malware
            - '\SearchFilterHost.exe'
            - '\SearchProtocolHost.exe'
            - '\sndvol.exe'
            - '\wermgr.exe'
            - '\wwahost.exe'
        Protocol: tcp
        Initiated: 'true'
    condition: selection
False Positives
Unlikely

False positives are unlikely for most environments. High confidence detection.

MITRE ATT&CK

Other

detection.emerging-threats
Rule Metadata
Rule ID
cae6cee6-0244-44d2-84ed-e65f548eb7dc
Status
test
Level
high
Type
Emerging Threat
Created
Fri Oct 27
Modified
Fri Jan 26
Path
rules-emerging-threats/2023/Malware/Pikabot/net_connection_win_malware_pikabot_rundll32_activity.yml
Raw Tags
attack.command-and-controlattack.t1573detection.emerging-threats
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