Performs a killall Terminal to kill the running script’s terminal window.Executes the payload using open with the passed arguments “s” “$session_guid” and “$volume_name”.Creates a directory in /tmp to store the payload and unzips the password-protected payload (note: the zip password is hardcoded in the script per sample).
#HOW TO DISABLE GATEKEEPER ON MAC ZIP FILE#
Attempts to download the zip file payload using curl.Creates a custom URL using the information generated in the previous two steps and downloads the second stage payload.Generates a “Session GUID” using uuidgen.Collects system information such as the macOS version and IOPlatformUUID (a unique identifier for the system).This new Shlayer variant unearthed by Carbon Black’s Threat Analysis Unit (TAU) targets all macOS releases up to the latest 10.14.3 Mojave, and will arrive on the targets' machines as a DMG, PKG, ISO, or ZIP files, some of them also signed with a valid Apple developer ID to make them look legitimate. Just like it did in the past, the new malware version is also distributed as a malicious Adobe Flash software update, but unlike the original version which was pushed through torrent websites, Shlayer is now spreading as fake update pop-ups on hijacked domains or legitimate sites clones, or as part of malvertising campaigns running on legitimate websites. Shlayer was first observed in action by Intego's research team which found it being distributed as part of a malware campaign during February 2018, disguising as a fake Adobe Flash Player installer like many other malware families targeting the Mac platform. A new variant of the multi-stage Shlayer malware known to target macOS users has been observed in the wild, now being capable to escalate privileges using a two-year-old technique and to disable the Gatekeeper protection mechanism to run unsigned second stage payloads.