private rule WimmieShellcode : Wimmie Family { meta: description = "Wimmie code features" author = "Seth Hardy" last_modified = "2014-07-17" strings: // decryption loop $ = { 49 30 24 39 83 F9 00 77 F7 8D 3D 4D 10 40 00 B9 0C 03 00 00 } $xordecrypt = {B9 B4 1D 00 00 [8] 49 30 24 39 83 F9 00 } condition: any of them } private rule WimmieStrings : Wimmie Family { meta: description = "Strings used by Wimmie" author = "Seth Hardy" last_modified = "2014-07-17" strings: $ = "\x00ScriptMan" $ = "C:\\WINDOWS\\system32\\sysprep\\cryptbase.dll" wide ascii $ = "ProbeScriptFint" wide ascii $ = "ProbeScriptKids" condition: any of them } rule Wimmie : Family { meta: description = "Wimmie family" author = "Seth Hardy" last_modified = "2014-07-17" condition: WimmieShellcode or WimmieStrings }