Internet access was restored Monday for over 200,000 employees at Koninklijke Philips Electronics after the company was hit by the Nimda worm early last week.
IT personnel suspended access to the Web and the company Intranet for the entire staff Tuesday, after determining Nimda was to blame for unusual amounts of network traffic, said spokesman Jeremy Cohen.
"When the IT personnel saw the unusual increase in network activity, they shut down parts on the network to limit the spread (of Nimda). Internet access was restored Monday, the Intranet was back up after about 24 hours," he said.
Philips is in the process of assessing the impact of Nimda across the 60 or more countries in which it has operations.
The company had backups in place for Web-based electronic business systems, according to Cohen.
"We have maintained legacy IT systems, those we used before we switched to another electronic commerce solution. Initial indications are that Nimda only had a limited effect on IT systems and business," he said.
Nimda (admin spelled backwards) exploits known vulnerabilities in Microsoft's Outlook e-mail clients, Internet Explorer browser, and Internet Information Server (IIS) Web server software to spread via e-mail, Web sites, and across shared disks on networks. The worm was first discovered on Tuesday last week.
Philips has yet to determine how the virus got into its systems.
"We don't have detail on how it got on our networks. I understand it spreads through Web sites. We use Lotus Notes for e-mail," said Cohen, adding that e-mail service was not interrupted.
Another company in Amsterdam was deprived of Web access and e-mail. Staff at Het Financieele Dagblad, a Dutch financial newspaper, had to find other ways to receive articles from freelance writers and international correspondents, as Internet and e-mail was down for two days after Nimda struck, according to a report in the paper.
The outbreak of Nimda hasn't led to new Web use guidelines at Philips, but software is being updated, according to Cohen.
"All of our systems are being updated. When I logged on this morning I noticed a number of different updates being installed. IT staff have been sending through news on the situation, but no new usage guidelines," he said.
A number of antivirus companies have tools available to detect and remove Nimda.