UAC-0099 evolves MATCHBOIL C# downloader targeting Ukrainian transport, manufacturing and energy firms
ESET documented the evolution of MATCHBOIL, a custom C downloader used by the Russia-aligned cyberespionage group UAC-0099. Samples span April 2024 to April 2026, although CERT-UA first documented the malware in August 2025. Each iteration became more sophisticated, with new obfuscation, sandbox checks and persistence methods. All victims…