Sigma rule: PUA - Netcat Suspicious Execution

Rule

Title

PUA - Netcat Suspicious Execution

Status

test

Level

high

Author

frack113, Florian Roth (Nextron Systems)

Date

2021-07-21

Modified

2023-02-08

File

rules/windows/process_creation/proc_creation_win_pua_netcat.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects execution of Netcat. Adversaries may use a non-application layer protocol for communication between host and C2 server or among infected hosts within a network

Log source

product

windows

category

process_creation

Detection

selection_img:
    # can not use OriginalFileName as is empty
    Image|endswith:
        - '\nc.exe'
        - '\ncat.exe'
        - '\netcat.exe'
selection_cmdline:
    # Typical command lines
    CommandLine|contains:
        - ' -lvp '
        - ' -lvnp'
        - ' -l -v -p '
        - ' -lv -p '
        - ' -l --proxy-type http '
        # - ' --exec cmd.exe ' # Not specific enough for netcat
        - ' -vnl --exec '
        - ' -vnl -e '
        - ' --lua-exec '
        - ' --sh-exec '
condition: 1 of selection_*

False positives (as the rule lists them)

• Legitimate ncat use

Tags

• attack.command-and-control
• attack.t1095

MITRE ATT&CK ids this rule names

• T1095

References

• https://nmap.org/ncat/
• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1095/T1095.md
• https://www.revshells.com/

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