OSX/Leap.A!worm.im

Alias/esCME-4 [Mitre], OSX.Leap.A [NAV], OSX.Oomp.A [Ambrosia], OSX/Leap-A [Sophos]
Release DateFeb 16, 2006
Detection Availability
Active DatabaseExtended Database
FortiGatelowhigh
FortiClient
FortiMailN/A
Current Antivirus Definition Database Version: 12.202
CVECME-4
Description

Visible Symptoms

  • Presence of the file "latestpics.gz" or similar, in the /tmp folder

Detailed Analysis

This virus is a proof of concept coded for OS X systems. This virus has two main spreading vectors:

  • iChat file attachment receipt from an infected user
  • as a companion virus on an already infected system

The virus author intended this threat to function as a companion virus, or basically, to first load itself, and then launch "tagged" binaries that have become infected. Due to bugs in the code, the infected app doesn't run.

iChat Propagation
This threat could arrive via an infected iChat "buddy list" contact. The file may be received as "latestpics.tgz" or similar. If the recipient attempts to open the archive file, the resulting file could resemble a picture file. On an uninfected system that is not running as the Administrator, attempts to run the virus will be slowed by the request by the system to enter the Admin password. This is due to the nature of the virus running as an executable instead of a (data) picture file.

The virus copies itself to the /tmp folder for storage, and iterates iChat contacts, then attempts to send itself to contacts that are logged on.

Companion Virus Propagation
This virus intends to infect binaries and pass execution on to infected after first running the virus code. Due to an algorithmic bug in the virus code, the infected (original app) code is never executed.

Miscellaneous
The virus sets an extended attribute (metadata) value for infected binaries to "loompa", very likely a reference to the children's classic "Willy Wonka".

Reference: ID - 166942