Sigma rule: Network Connection Initiated By PowerShell Process

Rule

Title

Network Connection Initiated By PowerShell Process

Status

test

Level

low

Author

Florian Roth (Nextron Systems)

Date

2017-03-13

Modified

2024-03-13

File

rules-threat-hunting/windows/network_connection/net_connection_win_powershell_network_connection.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a network connection that was initiated from a PowerShell process.
Often times malicious powershell scripts download additional payloads or communicate back to command and control channels via uncommon ports or IPs.
Use this rule as a basis for hunting for anomalies.

Log source

product

windows

category

network_connection

Detection

selection:
    Image|endswith:
        - '\powershell.exe'
        - '\pwsh.exe'
    Initiated: 'true'
filter_main_local_ip:
    DestinationIp|cidr:
        - '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
    User|contains: # covers many language settings
        - 'AUTHORI'
        - 'AUTORI'
filter_main_msrange:
    DestinationIp|cidr:
        - '20.184.0.0/13'
        - '51.103.210.0/23'
condition: selection and not 1 of filter_main_*

False positives (as the rule lists them)

• Administrative scripts
• Microsoft IP range
• Additional filters are required. Adjust to your environment (e.g. extend filters with company's ip range')

Tags

• attack.execution
• attack.t1059.001
• detection.threat-hunting

MITRE ATT&CK ids this rule names

• T1059.001

References

• https://www.youtube.com/watch?v=DLtJTxMWZ2o

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