Threat Huntmediumtest

Dfsvc.EXE Network Connection To Non-Local IPs

Detects network connections from "dfsvc.exe" used to handled ClickOnce applications to non-local IPs

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Launch
Nasreddine Bencherchali (Nextron Systems)Created Mon Jun 12Updated Tue Mar 123c21219b-49b5-4268-bce6-c914ed50f09cwindows
Hunting Hypothesis
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 Logic2 selectors
detection:
    selection:
        Image|endswith: '\dfsvc.exe'
        Initiated: 'true'
    filter_main_local_ip:
        DestinationIp|cidr: # Ranges excluded based on https://github.com/SigmaHQ/sigma/blob/0f176092326ab9d1e19384d30224e5f29f760d82/rules/windows/network_connection/net_connection_win_dllhost_net_connections.yml
            - '127.0.0.0/8'
            - '10.0.0.0/8'
            - '169.254.0.0/16'  # link-local address
            - '172.16.0.0/12'
            - '192.168.0.0/16'
            - '::1/128'  # IPv6 loopback
            - 'fe80::/10'  # IPv6 link-local addresses
            - 'fc00::/7'  # IPv6 private addresses
    condition: selection and not 1 of filter_main_*
False Positives

False positives are expected from ClickOnce manifests hosted on public IPs and domains. Apply additional filters for the accepted IPs in your environement as necessary

MITRE ATT&CK

Other

detection.threat-hunting
Rule Metadata
Rule ID
3c21219b-49b5-4268-bce6-c914ed50f09c
Status
test
Level
medium
Type
Threat Hunt
Created
Mon Jun 12
Modified
Tue Mar 12
Path
rules-threat-hunting/windows/network_connection/net_connection_win_dfsvc_non_local_ip.yml
Raw Tags
attack.executionattack.t1203detection.threat-hunting
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