file where host.os.type == "macos" and event.action == "modification" and
file.name like~ "com.apple.screensaver.*.plist" and
file.path like (
"/Users/*/Library/Preferences/ByHost/*",
"/Library/Managed Preferences/*",
"/System/Library/Preferences/*"
) and
(
process.code_signature.trusted == false or
process.code_signature.exists == false or
/* common script interpreters and abused native macOS bins */
process.name like~ (
"curl",
"mktemp",
"tail",
"funzip",
"python*",
"osascript",
"perl"
)
) and
/* Filter OS processes modifying screensaver plist files */
not process.executable like (
"/usr/sbin/cfprefsd",
"/usr/libexec/xpcproxy",
"/System/Library/CoreServices/ManagedClient.app/Contents/Resources/MCXCompositor",
"/System/Library/CoreServices/ManagedClient.app/Contents/MacOS/ManagedClient"
)
Install detection rules in Elastic Security
Detect Screensaver Plist File Modified by Unexpected Process 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).