Add malicious crate rustdecimal (#1317)

Author: pinkforest

crates/rustdecimal/RUSTSEC-0000-0000.md

@@ -0,0 +1,65 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "rustdecimal"
+date = "2022-05-10"
+url = "https://groups.google.com/g/rustlang-security-announcements/c/5DVtC8pgJLw?pli=1"
+categories = ["code-execution"]
+keywords = ["typosquatting"]
+[versions]
+patched = []
+```
+
+# malicious crate `rustdecimal`
+
+The Rust Security Response WG and the crates.io team [were notified][1] on
+2022-05-02 of the existence of the malicious crate `rustdecimal`, which
+contained malware. The crate name was intentionally similar to the name of the
+popular [`rust_decimal`][2] crate, hoping that potential victims would misspell
+its name (an attack called "typosquatting").
+
+To protect the security of the ecosystem, the crates.io team permanently
+removed the crate from the registry as soon as it was made aware of the
+malware. An analysis of all the crates on crates.io was also performed, and no
+other crate with similar code patterns was found.
+
+Keep in mind that the [`rust_decimal`][2] crate was **not** compromised, and it
+is still safe to use.
+
+## Analysis of the crate
+
+The crate had less than 500 downloads since its first release on 2022-03-25,
+and no crates on the crates.io registry depended on it.
+
+The crate contained identical source code and functionality as the legit
+`rust_decimal` crate, except for the `Decimal::new` function.
+
+When the function was called, it checked whether the `GITLAB_CI` environment
+variable was set, and if so it downloaded a binary payload into
+`/tmp/git-updater.bin` and executed it. The binary payload supported both Linux
+and macOS, but not for Windows.
+
+An analysis of the binary payload was not possible, as the download URL didn't
+work anymore when the analysis was performed.
+
+## Recommendations
+
+If your project or organization is running GitLab CI, we strongly recommend
+checking whether your project or one of its dependencies depended on the
+`rustdecimal` crate, starting from 2022-03-25. If you notice a dependency on
+that crate, you should consider your CI environment to be compromised.
+
+In general, we recommend regularly auditing your dependencies, and only
+depending on crates whose author you trust. If you notice any suspicious
+behavior in a crate's source code please follow [the Rust security
+policy][3] and report it to the Rust Security Response WG.
+
+## Acknowledgements
+
+We want to thank GitHub user [`@safinaskar`][4] for identifying the
+malicious crate in [this GitHub issue][1].
+
+[1]: https://github.com/paupino/rust-decimal/issues/514#issuecomment-1115408888
+[2]: https://crates.io/crates/rust_decimal
+[3]: https://www.rust-lang.org/policies/security
+[4]: https://github.com/safinaskar