Microsoft UK's recently appointed chief security advisor, Ed Gibson, has admitted to being hit by that lowliest of online scams - the rogue dialler.

The scams are seen as mainly affecting the lowest rung of Internet users - beginners using dial-up connections without basic security software, such as a firewall, that would prevent infection or alert them to the dialler's activities. However, broadband users can also be affected via back-up modem connections.

However, the problem clearly isn't limited to Internet newbies, Gibson reportedly said at a trade conference last week. A rogue dialler recently cost Gibson £450 in phone bills, which BT is insisting he pay. Gibson told attendees at London "eConfidence: Spam and Scams" conference that more must be done about the rogue dialler problem.

It isn't clear how Gibson, a former senior FBI officer specialising in financial crime, was infected with the dialler software. Microsoft wasn't able to immediately comment.

Rogue diallers secretly install code on a user's system causing modems to connect to the Internet via a premium-rate number, whose profits are siphoned off to the scammers. Public outrage over the scams reached a high level about a year ago, and in recent weeks BT, the premium-rate regulator and the government have begun taking action to protect users, punish rogue dialler scammers more harshly, and to make it more difficult for scammers to get at premium-rate funds.

ICSTIS, the regulator of premium-rate services in the UK, last month announced that telephone providers will now be forced to delay transferring funds to premium-rate number holders for 30 days. The measure is expected to make it harder for the scams to operate. Previously number operators were paid within a couple of days.

In June, the government announced that rogue dialler scammers could face fines of up to £250,000 under new government proposals backed by ICSTIS. BT, for its part, earlier this year introduced free software called Modem Protection designed to stop rogue diallers. The software alerts users whenever the computer attempts to dial a number not on the user's "safe" list.

Gibson started with Microsoft in July, after 20 years in senior positions with the FBI. He has served as the FBI's assistant legal attaché in the UK for the past five years, before which he spent 15 years as an investigating agent specialising in asset tracing and confiscation, money laundering, intellectual property theft and financial crime.

Over the past five years Gibson has become known in the UK for his cybercrime lectures, beginning each lecture wearing dark glasses.

Gibson reports to Nick McGrath, head of platform strategy for Microsoft UK. He replaced the more technically-oriented Stuart Okin, who left Microsoft for Accenture last year.