windows(opens in a new tab or window)
endpoint(opens in a new tab or window)
file where host.os.type == "windows" and event.type != "deletion" and file.path != null and
file.name : ("amsi.dll", "amsi") and
not file.path : (
"?:\\$SysReset\\CloudImage\\Package_for_RollupFix*",
"?:\\Windows\\system32\\amsi.dll",
"?:\\Windows\\Syswow64\\amsi.dll",
"?:\\$WINDOWS.~BT\\DUImageSandbox\\*",
"?:\\$WINDOWS.~BT\\NewOS\\Windows\\WinSXS\\*",
"?:\\$WINDOWS.~BT\\NewOS\\Windows\\servicing\\LCU\\*",
"?:\\$WINDOWS.~BT\\Work\\*\\*",
"?:\\$WINDOWS.~BT\\Store\\Offline\\File\\C$\\Windows\\SoftwareDistribution\\Download.bak\\*",
"?:\\Windows\\CbsTemp\\*\\f\\amsi.dll",
"?:\\Windows\\SoftwareDistribution\\Download\\*",
"?:\\Windows\\WinSxS\\amd64_microsoft-antimalware-scan-interface_*\\amsi.dll"
) and
not
(
process.executable : "C:\\Windows\\System32\\wbengine.exe" and
file.path : (
"\\Device\\HarddiskVolume??\\Windows\\system32\\amsi.dll",
"\\Device\\HarddiskVolume??\\Windows\\syswow64\\amsi.dll",
"\\Device\\HarddiskVolume??\\Windows\\WinSxS\\*\\amsi.dll",
"\\\\?\\Volume{*}\\Windows\\WinSxS\\*\\amsi.dll",
"\\\\?\\Volume{*}\\Windows\\system32\\amsi.dll",
"\\\\?\\Volume{*}\\Windows\\syswow64\\amsi.dll"
)
)
Install detection rules in Elastic Security
Detect Suspicious Antimalware Scan Interface DLL in the Elastic Security detection engine by installing this rule into your Elastic Stack.
To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).