W32.Gaobot.UJ is a variant of W32.HLLW.Gaobot.gen.
It attempts to spread through network shares that have weak passwords and allows attackers to access an infected computer through an IRC channel.
The worm uses multiple vulnerabilities to spread, including:
W32.Gaobot.UJ is packed first with ASPack, and then with Morphine.
Click for a more detailed description of Rapid Release and Daily Certified virus definitions.