Nearly 800 computers in Norfolk, Virginia were recently hit by an unidentified form of data-destroying malware.

"The incident is still under investigation, but city officials say the attack may have been the result of a computer time bomb planted in advance by an insider or employee and designed to trigger at a specific date," writes Brian Krebs at Krebs on Security.

"Hap Cluff, director of the information technology department for the City of Norfolk, said the incident began on Feb. 9, and that the city has been working ever since to rebuild 784 PCs and laptops that were hit (the city manages roughly 4,500 systems total)," Krebs writes.

Click here to read the article at Krebs on Security.