title: Potential Netcat Reverse Shell Execution
id: 7f734ed0-4f47-46c0-837f-6ee62505abd9
status: test
description: Detects execution of netcat with the "-e" flag followed by common shells. This could be a sign of a potential reverse shell setup.
references:
    - https://pentestmonkey.net/cheat-sheet/shells/reverse-shell-cheat-sheet
    - https://www.revshells.com/
    - https://www.hackingtutorials.org/networking/hacking-netcat-part-2-bind-reverse-shells/
    - https://www.infosecademy.com/netcat-reverse-shells/
    - https://man7.org/linux/man-pages/man1/ncat.1.html
author: '@d4ns4n_, Nasreddine Bencherchali (Nextron Systems)'
date: 2023-04-07
tags:
    - attack.execution
    - attack.t1059
logsource:
    category: process_creation
    product: linux
detection:
    selection_nc:
        Image|endswith:
            - '/nc'
            - '/ncat'
    selection_flags:
        CommandLine|contains:
            - ' -c '
            - ' -e '
    selection_shell:
        CommandLine|contains:
            - ' ash'
            - ' bash'
            - ' bsh'
            - ' csh'
            - ' ksh'
            - ' pdksh'
            - ' sh'
            - ' tcsh'
            - '/bin/ash'
            - '/bin/bash'
            - '/bin/bsh'
            - '/bin/csh'
            - '/bin/ksh'
            - '/bin/pdksh'
            - '/bin/sh'
            - '/bin/tcsh'
            - '/bin/zsh'
            - '$IFSash'
            - '$IFSbash'
            - '$IFSbsh'
            - '$IFScsh'
            - '$IFSksh'
            - '$IFSpdksh'
            - '$IFSsh'
            - '$IFStcsh'
            - '$IFSzsh'
    condition: all of selection_*
falsepositives:
    - Unlikely
level: high

title: PUA - Netcat Suspicious Execution
id: e31033fc-33f0-4020-9a16-faf9b31cbf08
status: test
description: 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
references:
    - https://nmap.org/ncat/
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1095/T1095.md
    - https://www.revshells.com/
author: frack113, Florian Roth (Nextron Systems)
date: 2021-07-21
modified: 2023-02-08
tags:
    - attack.command-and-control
    - attack.t1095
logsource:
    category: process_creation
    product: windows
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_*
falsepositives:
    - Legitimate ncat use
level: high

title: Netcat The Powershell Version
id: c5b20776-639a-49bf-94c7-84f912b91c15
related:
    - id: bf7286e7-c0be-460b-a7e8-5b2e07ecc2f2
      type: derived
status: test
description: Adversaries may use a non-application layer protocol for communication between host and C2 server or among infected hosts within a network
references:
    - https://nmap.org/ncat/
    - https://github.com/besimorhino/powercat
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1095/T1095.md
author: frack113
date: 2021-07-21
modified: 2023-10-27
tags:
    - attack.command-and-control
    - attack.execution
    - attack.t1095
    - attack.t1059.001
logsource:
    product: windows
    category: ps_classic_start
detection:
    selection:
        Data|contains:
            - 'powercat '
            - 'powercat.ps1'
    condition: selection
falsepositives:
    - Unknown
level: medium