Details of the problem were posted yesterday afternoon on the Kaspersky website, but the good news is that patch for the issue is under active development and was expected to be rolled out today.

The problem for Kaspersky IT security software, Infosecurity notes, is that Adsense advertisements are in active use on thousands of smaller websites on the internet.

Anyone encountering a web page with an Adsense ad on it will see their Kaspersky security software display a warning that a Trojan infection is on the page, when, in fact, there is no malware.

Depending on the software's settings, the page being accessed is blocked by the IT security software.

In its support posting, Kaspersky says that its Internet Security 2009 and 2010, as well as Anti-Virus 2009 and 2010 applications, plus Anti-Virus 6.0 for Windows Workstations MP4 are affected by the problem.

"In such cases Kaspersky Lab products may display the message that the requested object is infected with one of the following viruses:

Backdoor.Win32.Hupigon.jrpd
Trojan.Win32.Generic
Trojan.Win32.Swisyn.nik
Win32.KillFiles.b
Win32.StartPage.c
Win32.StartPage.d
Win32.StartPage.e
Win32.StartPage.f
Win32.StartPage.g
Win32.StartPage.h
Win32.Trojan-Downloader.Generic.ac
Win32.Trojan-Downloader.Generic.ad
Win32.Trojan-Downloader.Generic.ai

"Such detections of the viruses mentioned above on some Google web pages are false alarms", said the company.

"Kaspersky Lab would like to apologise for any inconvenience this problem may have caused users. The company is continually improving its procedures for testing products and releasing updates to prevent such errors from occurring in future."