Washington, D.C ? A computer worm that infiltrated thousands of computers last month is expected to awaken today, destroying documents and files on infected machines and networks, Microsoft Corp. and computer security experts said.

The worm is variously named “Nyxem.D,” “MyWife.E,” “Blackmal.E,” and the “Kama Sutra worm” by anti-virus companies. It also is known as “Blackworm.” On the third day of each month, it will seek and delete many file types found on infected Windows computers, including Adobe PDF files and Microsoft Word, Excel and PowerPoint documents.

Microsoft advises customers who think their computers may be infected with the worm to scan them with up-to-date anti-virus software or run a “protection scan” at the company’s Windows Live Safety Center Web site http://safety.live.com.