vbsbased_malware_infection

rule vbsbased_malware_infection {
 meta:
    author = "Emir Erdogan"
    description = "Visual Basic Script opens powershell and downloads malware from C2 server  License: https://github.com/Neo23x0/sigma/blob/master/LICENSE.Detection.Rules.md."
    reference = "https://tdm.socprime.com/tdm/info/virBVdTXxip5"
    version = "0.01"
    created = "2021-03-09"
    product = "windows"
    service = "sysmon"
    mitre = "T1064, T1086, T1179"

  events:
($selection.metadata.product_event_type = "1" and re.regex($selection.target.process.file.full_path, `.*powershell\.exe`) and $selection.principal.process.file.full_path = "C:\\Windows\\System32\\wscript.exe" and re.regex($selection.target.process.command_line, `\".*powershell\.exe\" iujby=\"tsgw\";iex \( [string][System\.Text\.Encoding]::ASCII\.GetString\([System\.Convert]::FromBase64String\( \(\(New-Object Net\.WebClient\)\.DownloadString.*`) and $selection.target.file.md5 = "SHA1=6CBCE4A295C163791B60FC23D285E6D84F28EE4C")

  condition:
    $selection
}