diff --git a/rules/windows/persistence_run_key_and_startup_broad.toml b/rules/windows/persistence_run_key_and_startup_broad.toml index 3e5351587..0e69b2078 100644 --- a/rules/windows/persistence_run_key_and_startup_broad.toml +++ b/rules/windows/persistence_run_key_and_startup_broad.toml @@ -1,7 +1,8 @@ [metadata] creation_date = "2020/11/18" maturity = "production" -updated_date = "2021/03/15" +updated_date = "2021/04/07" + [rule] author = ["Elastic"] @@ -22,8 +23,7 @@ timestamp_override = "event.ingested" type = "eql" query = ''' -/* uncomment length once stable */ -registry where /* length(registry.data.strings) > 0 and */ +registry where registry.data.strings != null and registry.path : ( /* Machine Hive */ "HKLM\\Software\\Microsoft\\Windows\\CurrentVersion\\Run\\*", @@ -38,12 +38,15 @@ registry where /* length(registry.data.strings) > 0 and */ "HKEY_USERS\\*\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\Run\\*", "HKEY_USERS\\*\\Software\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\Shell\\*" ) and - /* add here common legit changes without making too restrictive as this is one of the most abused AESPs */ + /* add common legitimate changes without being too restrictive as this is one of the most abused AESPs */ not registry.data.strings : "ctfmon.exe /n" and not (registry.value : "Application Restart #*" and process.name : "csrss.exe") and - user.domain != "NT AUTHORITY" and - not registry.data.strings : ("C:\\Program Files\\*.exe", "C:\\Program Files (x86)\\*.exe") and - not process.executable : ("C:\\Windows\\System32\\msiexec.exe", "C:\\Windows\\SysWOW64\\msiexec.exe") + user.id not in ("S-1-5-18", "S-1-5-19", "S-1-5-20") and + not registry.data.strings : ("?:\\Program Files\\*.exe", "?:\\Program Files (x86)\\*.exe") and + not process.executable : ("?:\\Windows\\System32\\msiexec.exe", "?:\\Windows\\SysWOW64\\msiexec.exe") and + not (process.name : "OneDriveSetup.exe" and + registry.value : ("Delete Cached Standalone Update Binary", "Delete Cached Update Binary", "amd64", "Uninstall *") and + registry.data.strings : "?:\\Windows\\system32\\cmd.exe /q /c * \"?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\*\"") ''' @@ -64,4 +67,3 @@ reference = "https://attack.mitre.org/techniques/T1547/001/" id = "TA0003" name = "Persistence" reference = "https://attack.mitre.org/tactics/TA0003/" -