Updated UK-based consumer finance website MoneySavingExpert.com was forced to pull most of its services over the weekend as a result of an ongoing denial of service attack.

The site was hit at 1700 on Friday hours before launching a high-profile campaign against insurance rip-offs. Services were largely restored by 1000 on Monday.

The attack has left a guide to reclaiming mis-sold Payment Protection Insurance (PPI) temporarily unavailable. Martin Lewis, who runs the site, said the mis-selling of PPI to people applying for personal loans and credit cards is rife. He recently started a campaign to reclaim the cost of loan and card insurance.

MoneySavingExpert.com - a self-billed "consumer revenge" site - claims it is used by over three million people in the UK a month. The assault on the site by unknown assailants came on the same day as the launch of Lewis's PPI reclaim campaign.

Lewis reckons the timing of the attack is "probably not a coincidence" . The perpetrators of the attack remain unidentified. Sometimes such attacks are motivated by blackmail but Lewis said it has received no approach from those behind the assault.

MoneySavingExpert.com has campaigned on a variety of issues beyond its recent PPI push, activities that have earned its share of enemies over the years.

"We've cost some people a lot of money by telling consumers what to do," Lewis told El Reg.

Denial of service attacks involve rendering websites unusable, sometimes for prolonged periods that can reach into days. Attackers commonly start off with cruder forms of attack (such as a SYN Flood) before increasing the sophistication of the attack to confuse and confound a site's defenders.

Bringing the site back online after what Lewis described as a "phenomenal DDoS attack" proved a tall order. Minor glitches remain. "We're doing well at repelling that for the main site; although doing it for the forums is much more difficult," he said.

However clever or sophisticated the attack might be, it's probably done little beyond temporarily delaying some PPI claims. The assault might even draw wider attention to the issue.

MoneySavingExpert.com's PPI reclaiming guide and free template letters are due to be included in its weekly MoneySaving email, or via Google's cache here, pending full restoration of the site. ®