# tokyoneon/Chimera

Chimera is a PowerShell obfuscation script designed to bypass AMSI and commercial antivirus solutions.

Repository: https://github.com/tokyoneon/Chimera
Canonical: https://ross.abutalabs.com/products/chimera
Homepage: https://null-byte.com/bypass-amsi-0333967/
Language: PowerShell
License Family: other
Topics: bypass-antivirus, antivirus-evasion, antivirus, attack, offensive-security, kali-scripts, kali-script, kali-linux, kali, information-security, reverse-shell, payload, payloads, penetration-testing, payload-generator, shell, shell-scripts, amsi
Last push: 2021-11-09T12:39:59+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 2192, "days_push": 1758, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1597, forks 257 (observed 2026-08-28T04:05:09.256804+00:00)

## What it is
Chimera is a PowerShell obfuscation script that transforms malicious PS1 payloads using string substitution and variable concatenation to bypass AMSI and antivirus detection signatures. It is an offensive security tool aimed at penetration testers demonstrating how trivial signature-based evasion can be.

## Use cases
- obfuscate powershell payloads to bypass antivirus
- bypass AMSI detection on Windows
- evade signature-based AV detection for red team engagements
- generate obfuscated reverse shell scripts for penetration testing
- test antivirus detection capabilities against obfuscated scripts

## When to choose
- you are a penetration tester or red teamer needing to evade signature-based AV on Windows targets
- you want to demonstrate AMSI bypass weaknesses in security assessments
- you need a quick, script-based PowerShell obfuscation tool on Kali Linux

## When to avoid
- you need defensive tooling or malware analysis rather than offensive evasion
- you require a maintained, supported product - the project has had no releases since 2021 and no license
- your target uses behavior-based or modern EDR detection rather than simple signatures
- obfuscating PowerShell is prohibited in your environment or jurisdiction

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: security, penetration-testing, vulnerability-scanning
- domain: security, penetration-testing
- platform: windows, cli
- tags: powershell-obfuscation, amsi-bypass, antivirus-evasion, offensive-security, payload-generator, red-team, linux

## Member repositories
- tokyoneon/Chimera (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:09.256804+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:54:01.086399+00:00, confidence not recorded.
  - readme: https://github.com/tokyoneon/Chimera (fetched 2026-08-28T04:05:09.256804+00:00, sha 86af4c9047df)
- Data as of 2026-08-30T08:39:29.467469+00:00.