The war of words between Russian anti-virus vendor Kaspersky Lab and rival Rising Tech, has intensified after Kaspersky slapped a defamation lawsuit on the Chinese anti-virus provider following its recent controversial comments.

The dispute began back in May, when Kaspersky’s anti-virus software identified a Rising Tech update program as a virus. The fault only affected those users with both Kaspersky’s and Rising’s anti-virus software installed, but it meant that the update element of Rising’s anti-spyware software was deleted.

“We fixed the problem as soon as we could,” said David Emm, senior technology consultant at Kaspersky.

However it seems that the Chinese vendor was not amused at all, and days later it alleged in a Chinese statement that Kaspersky’s anti-virus software had made 22 mistakes between November 2006 and May 2007.

“Rising were saying things about us which we weren’t happy about,” confirmed Emm. “In fact, what they were saying was so serious that our legal people felt we needed to take action.”

The Chinese subsidiary of Kaspersky therefore filed a lawsuit against Rising late last month, accusing Rising of violating Chinese law by telling users that Kaspersky’s software could damage their computers. In addition, it alleged that Rising defamed it by claiming the company engaged in anti-competitive practices and hired people to attack Rising in online forums and in the media.

The case is scheduled to be heard on Monday 23 July in Tianjin No.1 Intermediate People’s Court.

But this has not deterred the Chinese vendor, which responded to the Kaspersky lawsuit by escalating the situation, claiming that Kaspersky was the “king of false positives”. Rising Tech then detailed another six instances in the past two weeks where Kaspersky’s anti-virus software allegedly misidentified system files from several programs as malware.

Rising Tech did not respond to Techworld at the time of writing.

While the dispute is certainly making headlines, one industry watcher is not too concern about the number of false positives anti-virus software can generate. According to Charles Kolodgy, research director at IDC’s secure content and threat management products unit, it is very difficult to test every application to ensure that there are no false positives.

“When they are identified, the AV vendor normally corrects it quickly,” Kolodgy said. “With daily or even hourly signature updates, the fixes can occur quickly.” He believes that most users normally do not have competing anti-virus products on the same machine, because they are known to interfere with each other, “so normally this sort of problem shouldn’t lead to a legal battle.”

And looking forward, Kolodgy feels that the dispute should not greatly impact the anti-virus industry, for the exact reason that only one anti-virus engine should be running on a machine (however he warns this isn’t the case of spyware).