Buer malware rewritten in Rust language to curb detection Ferris, the Rust mascot Developers of the malicious downloader Buer have taken the unusual step of rewriting the malware in a lesser-known Rust programming language, presumably to avoid detection while also potentially slowing down investigative analysis. While itâs fairly common to find malware written in C, C+, Python and Java, threat actors have also been known to experiment with more obscure languages as a means to stay ahead of detection and forensics. But âit is unusual to see common malware written in a completely different way,â according to a blog post this week from Proofpoint.