Malicious code in proxy-check-i (PyPI)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (2da390c130eb840eb129a5d43faf0a64a0f0f602070243613aa0e2f8ea8f6d04) The package advertises itself as a wrapper for a 'qsshd executable' but the bundled Go binary is a reverse-SSH daemon that grants a remote operator persistent shell, exec, pty, and TCP port-forwarding on the installer's host. The entry point `proxy-check-i` (declared in the package's console_scripts, mapped to `qsshd.launcher:main`) uses `os.execv` to launch the bundled Go binary. The daemon establishes device identity by writing a `.device_lock` file under `$XDG_CONFIG_HOME`, `/dev/shm`, or `/tmp`, then repeatedly dials out to a relay via `github.com/mydearniko/overthing` (`tunnel.NewServer` with `RelayURI` and `ForwardAddr` pointing at the local SSH listener). SSH authentication only accepts a single hardcoded ed25519 public key embedded at build time via `//go:embed authorized_keys`, so only the key holder can connect. The reverse-connect design bypasses inbound firewalls. PyPI metadata is a cover story: PKG-INFO summary mentions only 'qsshd executable' with no README and no disclosure of SSH-server, authorized-keys, or outbound-relay behavior, so an installer cannot infer they are enabling a remote-shell daemon. Any host that runs `proxy-check-i` is remotely controllable by the key holder. ## Source: kam193 (dd01be5624206ed8c0a5ba9535c9a9e79ed8770b37eb9ebc381edbe73cb5e779) The embedded binary starts a relayed SSH-like server using a hardcoded authorized_key. Thanks to using a relay network, the attacked does not need to directly expose ports from the machine. --- Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers. Campaign: 2026-07-proxy-check-i Reasons (based on the campaign): - backdoor - The package contains code to execute remote commands (probably limited to a specific set) on the victim's machine.
AI Analysis
Technical Summary
The proxy-check-i PyPI package (versions 0.1.0 and 0.1.1) includes a bundled Go binary acting as a reverse-SSH daemon. This daemon is launched via the package's entry point 'proxy-check-i' which calls the binary using os.execv. The daemon creates a device lock file and repeatedly connects outbound to a relay server using the 'overthing' tunnel library, enabling remote shell access, command execution, pty allocation, and TCP port forwarding. SSH authentication is restricted to a single hardcoded ed25519 public key embedded at build time, allowing only the key holder to connect. This reverse connection design circumvents inbound firewall rules. The PyPI metadata omits any mention of the SSH server or relay behavior, preventing users from recognizing the malicious functionality. Consequently, hosts running this package are exposed to remote control by the attacker.
Potential Impact
Hosts that install and run proxy-check-i versions 0.1.0 or 0.1.1 are exposed to full remote control by an attacker possessing the embedded SSH private key. The attacker can gain persistent shell access, execute arbitrary commands, allocate pseudo-terminals, and forward TCP ports, effectively compromising the confidentiality, integrity, and availability of the affected system. The reverse-SSH design bypasses inbound firewall protections, increasing the risk of undetected remote compromise.
Mitigation Recommendations
No official patch or remediation is currently available for proxy-check-i. Users should immediately uninstall versions 0.1.0 and 0.1.1 of this package and avoid running the 'proxy-check-i' command. Since the malicious behavior is embedded in the package itself, removing the package and any associated binaries is necessary to eliminate the threat. Monitor for any unauthorized SSH connections using the embedded key and investigate any systems where this package was installed. Patch status is not yet confirmed — check the vendor or PyPI advisories for updates.
Malicious code in proxy-check-i (PyPI)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (2da390c130eb840eb129a5d43faf0a64a0f0f602070243613aa0e2f8ea8f6d04) The package advertises itself as a wrapper for a 'qsshd executable' but the bundled Go binary is a reverse-SSH daemon that grants a remote operator persistent shell, exec, pty, and TCP port-forwarding on the installer's host. The entry point `proxy-check-i` (declared in the package's console_scripts, mapped to `qsshd.launcher:main`) uses `os.execv` to launch the bundled Go binary. The daemon establishes device identity by writing a `.device_lock` file under `$XDG_CONFIG_HOME`, `/dev/shm`, or `/tmp`, then repeatedly dials out to a relay via `github.com/mydearniko/overthing` (`tunnel.NewServer` with `RelayURI` and `ForwardAddr` pointing at the local SSH listener). SSH authentication only accepts a single hardcoded ed25519 public key embedded at build time via `//go:embed authorized_keys`, so only the key holder can connect. The reverse-connect design bypasses inbound firewalls. PyPI metadata is a cover story: PKG-INFO summary mentions only 'qsshd executable' with no README and no disclosure of SSH-server, authorized-keys, or outbound-relay behavior, so an installer cannot infer they are enabling a remote-shell daemon. Any host that runs `proxy-check-i` is remotely controllable by the key holder. ## Source: kam193 (dd01be5624206ed8c0a5ba9535c9a9e79ed8770b37eb9ebc381edbe73cb5e779) The embedded binary starts a relayed SSH-like server using a hardcoded authorized_key. Thanks to using a relay network, the attacked does not need to directly expose ports from the machine. --- Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers. Campaign: 2026-07-proxy-check-i Reasons (based on the campaign): - backdoor - The package contains code to execute remote commands (probably limited to a specific set) on the victim's machine.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The proxy-check-i PyPI package (versions 0.1.0 and 0.1.1) includes a bundled Go binary acting as a reverse-SSH daemon. This daemon is launched via the package's entry point 'proxy-check-i' which calls the binary using os.execv. The daemon creates a device lock file and repeatedly connects outbound to a relay server using the 'overthing' tunnel library, enabling remote shell access, command execution, pty allocation, and TCP port forwarding. SSH authentication is restricted to a single hardcoded ed25519 public key embedded at build time, allowing only the key holder to connect. This reverse connection design circumvents inbound firewall rules. The PyPI metadata omits any mention of the SSH server or relay behavior, preventing users from recognizing the malicious functionality. Consequently, hosts running this package are exposed to remote control by the attacker.
Potential Impact
Hosts that install and run proxy-check-i versions 0.1.0 or 0.1.1 are exposed to full remote control by an attacker possessing the embedded SSH private key. The attacker can gain persistent shell access, execute arbitrary commands, allocate pseudo-terminals, and forward TCP ports, effectively compromising the confidentiality, integrity, and availability of the affected system. The reverse-SSH design bypasses inbound firewall protections, increasing the risk of undetected remote compromise.
Mitigation Recommendations
No official patch or remediation is currently available for proxy-check-i. Users should immediately uninstall versions 0.1.0 and 0.1.1 of this package and avoid running the 'proxy-check-i' command. Since the malicious behavior is embedded in the package itself, removing the package and any associated binaries is necessary to eliminate the threat. Monitor for any unauthorized SSH connections using the embedded key and investigate any systems where this package was installed. Patch status is not yet confirmed — check the vendor or PyPI advisories for updates.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-10100
- Osv Schema Version
- 1.7.4
- Aliases
- []
- Ecosystems
- ["PyPI"]
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a50ba4568715ace4357e5d4
Added to database: 07/10/2026, 09:24:21 UTC
Last enriched: 07/10/2026, 09:36:45 UTC
Last updated: 07/26/2026, 19:34:13 UTC
Views: 32
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