arrayrefcrates.io
arrayref is a confirmed malicious crates.io package (MAL-2026-14336) that opens a backdoor for remote access (malicious version 0.3.10). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in arrayref (crates.io)
What this malware does
arrayref 0.3.10 was published to crates.io from a maintainer account (droundy) that appears to be compromised. Unlike every prior release, 0.3.10 declares a dependency on the malicious crate proc-macro1. The arrayref source itself is unchanged genuine macro code, but Cargo compiles the declared dependency, so building any project that resolves arrayref 0.3.10 pulls in and builds proc-macro1, whose build script downloads and executes an architecture-specific remote binary at build time from https://23.254.165.112:9089/ and passes 23.254.165.112:443 as a command-and-control address. Part of a coordinated crates.io campaign on 2026-08-20 that also trojanized internment and append-only-vec. The malicious release has been removed from crates.io; releases 0.3.9 and earlier are unaffected.
Malicious versions
Detection & response playbook
Backdoor / remote accessFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for arrayref (version 0.3.10). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging arrayref across your stack and pipelines.
If you installed it — respond
arrayref establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If arrayref was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks arrayref before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
References
Credits
- SafeDep · finder
- jhobern · reporter
Detect & block this
O3 blocks arrayref-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.