bashka
A drop-in safety guard for the curl … | bash install pattern. Bashka parses the incoming script, scores it against many different checks, follows forwarded scripts so every layer is analyzed and if it found some unsafety it gives you an easy way to read a script or analyze using your AI agent.
Useage is simple as adding ka after the standard installation script
curl -fsSL https://pyenv.run | bashka
https://github.com/user-attachments/assets/f1a55ede-f1a7-4b9f-a512-d395b30bc53f
Install
Install via bash. One last time.
curl --proto '=https' --tlsv1.2 -fsSL https://bashka.dmtrkovalenko.dev | bash
We guarantee absolute safety of this script! Read it yourself
Or skip bash entirely. The following methods install a release binary or build from source:
Homebrew (macOS and Linux):
brew install bashka
Cargo: from crates.io, or prebuilt via cargo-binstall:
cargo install bashka # builds from source
cargo binstall bashka # downloads the release binary
mise
mise use -g github:dmtrKovalenko/bashka # prebuilt binary from GitHub releases
mise use -g cargo:bashka # or build from crates.io
Manual: grab bashka-<target> from the releases page, check it against the .sha256 next to it, and drop it on your PATH.
However you installed it, bashka manages itself: bashka update bashka re-runs the installer and bashka remove bashka (or bashka uninstall bashka) deletes the binary, the config and the install registry.
Flags
Findings come in four kinds: 💀 💀 (critically malicious, blocks hard), 🚩 red (dangerous),
🟡 yellow (advisory, never changes the verdict), ✅ green (good-citizen signal).
| kind |
id |
what it looks for |
| 💀 |
exfil_destination |
sends data to webhook.site/Discord/Telegram/ngrok/paste sites, the cloud-metadata IP, or a raw IP (Codecov, Shai-Hulud) |
| 💀 |
credential_theft |
reads SSH keys, cloud credentials, .netrc, the keychain |
| 💀 |
exfiltration |
environment or secrets sent to the network (env | curl, curl -d "$TOKEN") |
| 💀 |
reverse_shell |
backdoors: /dev/tcp, nc -e, socat EXEC, mkfifo pipe-to-shell |
| 🟢 |
checksum |
download digest checked: sha256sum -c, $(shasum …) compared, openssl dgst |
| 🟢 |
cleanup_artifacts |
trap … EXIT, or rm of a mktemp path |
| 🟢 |
https_only |
every download URL uses HTTPS |
| 🟢 |
install_dir |
installs into /usr/local/bin or ~/.local/bin |
| 🟢 |
privilege_escalation |
(🟢) never escalates; (🟡) uses sudo/doas. Some scripts genuinly need sudo and you will be prompted for it. |
| 🟢 |
strict_mode |
set -euo pipefail |
| 🟢 |
tls_hardening |
curl pins HTTPS-only and TLS 1.2+ (--proto '=https' --tlsv1.2) |
| 🟢 |
trusted_domains |
HTTPS downloads from GitHub, or the same domain the script was fetched from |
| 🟢 |
verify |
signature verified: gpg --verify, cosign, minisign, openssl dgst -verify |
| 🔴 |
anti_forensics |
hides tracks: HISTFILE=/dev/null, history -c, log truncation, journalctl --vacuum, killing EDR/audit agents |
| 🔴 |
banned_commands |
rm -rf /, dd of=/dev/*, mkfs, fork bomb, chmod -R 777 |
| 🔴 |
domain_refs |
plaintext HTTP, raw-IP hosts, URL shorteners |
| 🔴 |
env_hijack |
hijacks auto-run hooks: BASH_ENV/PROMPT_COMMAND/LD_PRELOAD/NODE_OPTIONS --require, sitecustomize.py |
| 🔴 |
git_hooks |
repoints git execution: core.hooksPath, core.fsmonitor, alias.x '!cmd', or writes into .git/hooks |
| 🔴 |
insecure_tls |
certificate checks off: curl -k, --no-check-certificate, GIT_SSL_NO_VERIFY |
| 🔴 |
install_name |
downloads files but nothing names the software (no URL hint, product variable, GitHub repo or bin target); yellow when the script takes the project from its arguments |
| 🔴 |
install_target |
downloads files but never names where they are installed |
| 🔴 |
macos_bypass |
strips Gatekeeper quarantine (xattr … com.apple.quarantine), tampers with TCC; osascript … hidden answer password phish is 💀 |
| 🔴 |
max_commands |
more commands than limit |
| 🔴 |
not_a_script |
the body is an HTTP redirect stub, an HTML/JSON page, or has no recognizable command (fetch with curl -fsSL) |
| 🔴 |
obfuscation |
eval of opaque code (eval "$CMD", eval $(…)), decode-then-execute pipelines |
| 🔴 |
package_managers |
pulls code from npm/npx/pip/cargo/go/gem/brew/docker or editor extensions; 🔴 on URL/git/mutable ref/foreign registry/--privileged, yellow on a plain global install |
| 🔴 |
path_suspicious |
PATH gains a temp, relative or world-writable directory |
| 🔴 |
auto_update |
writes a launcher to disk (shebang heredoc) that downloads by itself every time it runs: self-updating, never reviewed again |
| 🔴 |
dynamic_download |
fetches whatever address another command returns (curl "$(get url)", usually a field from a server reply); URLs the script names itself, even with $VERSION filled in, are fine |
| 🔴 |
remote_exec |
fetch->exec forward sinks (drives chain following) |
| 🔴 |
scheduled_tasks |
schedules code via cron, at, systemd timers, autostart or rc.local |
| 🔴 |
security_tampering |
disables firewall/SELinux/AppArmor/Gatekeeper/SIP |
| 🔴 |
self_extract |
reads its own bytes ($0) with sed/tail/dd/base64 and pipes the result into a shell |
| 🔴 |
sensitive_write |
writes to shell rc files, ~/.ssh, /etc/sudoers, crontab |
| 🔴 |
staged_installer |
downloads a program and runs it to do the install; the second stage is opaque to review |
| 🔴 |
telemetry |
sends data out (POST/--data, or analytics URLs); notes machine details in the body (uname, hostname) and a UUID saved as a persistent id |
| 🔴 |
unicode_tricks |
invisible, bidi, or homoglyph characters in a command name or URL, or a punycode host |
| 🔴 |
unsafe_rm |
rm -rf "$VAR/" where the variable may be empty and there is no guard or set -u |
| 🔴 |
upload_exfil |
uploads files (curl -T, -F @file, --data @file), copies out via scp/rsync, or DNS-exfil via dig $(…) |
| 🟡 |
checksum |
green if checks a digest, yellow if downloads are unverified |
| 🟡 |
many_downloads |
fetches from more than limit distinct URLs (default 2) |
| 🟡 |
mutable_refs |
downloads from master/main/HEAD/latest instead of a pinned version |
| 🟡 |
package_repos |
adds apt/yum/zypper repositories or signing keys |
| 🟡 |
persistence |
installs systemd/launchd services or init scripts |
CLI
Some of the additional commands
bashka list [--long] # table of software installed through bashka
bashka info <name> # everything recorded about one package
bashka update <name> # re-fetch the recorded installer and run it again
bashka remove <name> [--dry-run] # delete every recorded binary and created directory, forget the package (alias: uninstall)
bashka flags # list every registered flag with its options
bashka config init # print default configuration
Install registry
bashka writes a lock file of everything it installed to $XDG_DATA_HOME/bashka/installed.toml
(~/.local/share/bashka/installed.toml; BASHKA_LOCKFILE overrides the path). er that exits
non-zero leaves no record.
bashka list prints package list, inspired by pacman -Q:
NAME VERSION INSTALLED UPDATED FILES SOURCE
mise 2026..1 2026-0-15 - 1 https://mise.run
uv 0.9.2 2026-09-01 2026-09-15 2 https://astral.sh/uv/install.sh
demo 0.0.0-unknown 2026-09-15 - 2 (1 missing) <stdin>
bashka info <name> (or bashka list --long for all) shows the full record in pacman -Qi style, with each binary and created directory on its own line and missing paths marked.
bashka remove <name> deletes the recorded binaries and created directories, then drops the entry. There is a possibility that bashka couldn't track where the file is installed (which is a red flag) but after your approval it will still be tracked but during the uninstall the binary files wouldn't be deleted.
bashka update <name> fetches the recorded URL again and runs it through the full review with the recorded options and shell arguments.
Configuration
~/.config/bashka/config.toml is deep-merged over the embedded data/defaults.toml.
[flags]
strict_mode = false
max_commands = { limit = 200 }
trusted_domains = { additional_domains = ["get.example.com"] }
[interaction]
on_red = "ask" # ask | abort | proceed
follow_remote = "always" # ask | always | never
descend = "hybrid" # hybrid | fetch_ahead | shim
max_depth = 5
[ui]
icons = "emoji" # emoji | nerd | ascii
animations = true # spinners while fetching forwards and on hand-off
Limitations
- Bash is Turing-complete. Even though we try to detect obfuscation it can evade static analysis.
- The shim intercepts
bash/sh resolved through PATH but /bin/bash bypasses it.
trusted_domains keeps a deliberately strict allowlist (GitHub only). Everything else is
trusted only when it matches the domain the script was fetched from. Trusted domains can be modified via cofig using trusted_domains = { additional_domains = ["get.acme.io"] }.- A server may serve different bytes at run time than at fetch-ahead.
- The install registry only sees executables that land in the watched directories. If bashka couldn't detect where the binaries went, but you still approved it - we won't be able to manage and uninstall the binary
License
MIT and opensource. Support my work at https://github.com/sponsors/dmtrKovalenko
bashka 是针对 curl | bash 这种安装方式的安全防护工具:它会解析传入的安装脚本,用大量检查项给它打分,并跟踪脚本转发调用的其他脚本,确保每一层都得到分析。