Here's a cautionary tale about the importance of revoking network passwords after letting IT workers go: The U.S. subsidiary of Japanese pharmaceutical firm Shionogi lost 15 VMware host systems running everything from email to financial services for days after a laid-off employee used a secret vSphere console to bring down the system.

The former employee, Jason Cornish, was able to log into the company's network remotely via a Wi-Fi link at a McDonald's in Smyrna, Ga., reports IDG News Service's Robert McMillan.

Cornish pleaded guilty to charges of computer intrusion related to bringing down the servers. The Shionogi subsidiary, in Florham Park, N.J., was using the VMware systems for tracking orders, email, financial services and other functions, and its operations were effectively frozen for several days, according to court filings by the U.S. Department of Justice. Employees couldn't communicate with each other, write checks or send products.

The former employee had gotten into a dispute with managers and resigned in July 2010, but he continued working there as a consultant before being laid off along with other workers.

Sitting at a McDonald's, he managed to log into Shionogi's network and start up a management console that he had secretly deployed on the network. He then eliminated 88 servers from the VMware host systems. 

For more:
- see Robert McMillan's article at InfoWorld

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