The makers of the Downadup worm, the fastest-spreading malware in recent years, are set to trigger part of the worm’s payload on 1^st April.

The worm, also known as Kido or Conficker, spreads through network shares and via removable storage devices, such as USB thumb drives, using the AutoRun function in Windows.  With an estimated 10,000,000-plus machines infected by the worm at its peak, the worm’s authors are reportedly gearing up for the next phase of the attack.

The trojan downloaded by the worm onto infected machines is programmed to begin connecting to 50,000 different web domains on 1 April to receive updated copies or other malware, according to antivirus researchers.  This tactic is an attempt to outsmart antivirus measures, and ensure the next phase of infection has a chance of success.

So with under two weeks to go before 1^st April, our advice, and the advice from the security industry as a whole, is to apply the Microsoft patch that closes the vulnerability exploited by the worm, and update your antivirus software.  There are also free Downadup-removal tools available on the web.  Don’t be an April fool!