rule macro_GandCrab_Ursnif_dropper_2019_Q1 : TAU Trojan Ecrime Ransomware { meta: author = "Carbon Black TAU" //jmyers date = "2019-Jan-14" description = "Designed to catch PowerShell encoded command in Word Shape box as alternative text" link = "" rule_version = 1 yara_version = "3.7.0" Confidence = "Prod" Priority = "Medium" TLP = "White" exemplar_hashes = "0a3f915dd071e862046949885043b3ba61100b946cbc0d84ef7c44d77a50f080,cc5a14ff026ee593d7d25f213715b73833e6b9cf71091317121a009d5ad7fc36" strings: $s1 = "powershell.exe -NoP -Exec Bypass -EC " wide condition: all of them and uint16(0) == 0xCFD0 } rule GandCrab_Ursnif_PowerShell_cradle_2019_Q1 : TAU TROJAN Ecrime Ransomware { meta: author = "Carbon Black TAU" //jmyers date = "2019-Jan-14" description = "Designed to catch PowerShell cradle from campaign" link = "" rule_version = 1 yara_version = "3.7.0" Confidence = "Prod" Priority = "Medium" TLP = "White" exemplar_hashes = "3b59549507e0e3cfb4a363a306bf6eb4d26995066df643e1fc8e4e11eaffa7f9,debe4cb5645f10e6b6383838c25f26781a61acb536d2246cdf8dc33bbc1a2414" strings: $s1 = "If($ENV:PROCESSOR_ARCHITECTURE -contains 'AMD64')" $s2 = "$Env:WINDIR\\SysWOW64\\WindowsPowerShell" $s3 = "new-object net.webclient" $s4 = "downloadstring" $s5 = "Invoke" $s6 = "Sleep" condition: 4 of ($s*) and filesize < 2KB }