import "pe" rule SUSP_VCRuntime_Sideloading_Indicators_Aug23 { meta: description = "Detects indicators of .NET based malware sideloading as VCRUNTIME140 with .NET DLL imports" author = "Jonathan Peters" date = "2023-08-30" hash = "b4bc73dfe9a781e2fee4978127cb9257bc2ffd67fc2df00375acf329d191ffd6" score = 75 id = "00400122-1343-5051-af31-880a3ef1745d" condition: (filename == "VCRUNTIME140.dll" or filename == "vcruntime140.dll") and pe.imports("mscoree.dll", "_CorDllMain") } // rule SUSP_VCRuntime_Sideloading_Indicators_1_Aug23 { // meta: // description = "Detects indicators of .NET based malware sideloading as an unsigned VCRUNTIME140" // author = "Jonathan Peters" // date = "2023-08-30" // hash = "b4bc73dfe9a781e2fee4978127cb9257bc2ffd67fc2df00375acf329d191ffd6" // score = 75 // strings: // $fp1 = "Wine builtin DLL" ascii // condition: // (filename == "VCRUNTIME140.dll" or filename == "vcruntime140.dll") // and not pe.number_of_signatures == 0 // and not pe.signatures[0].issuer contains "Microsoft Corporation" // and not $fp1 // }