For the second time in less than a week, security vendor McAfee has issued an alert for W32/Chir.b@MM, a file infector targeted at several file formats. W32/Chir.b@MM is also able to spread using email techniques.

When the malware is started, it will immediately create a Mutex named "ChineseHacker-2" in order to ensure that there are not multiple instances of the malware executing at the same time. After this, W32/Chir.b will drop an instance of the pure infector in the windows folder, with the name: "runouce.exe"

More information can be found at this McAfee page.