DoubleClick undergoes security audit after hack attack
Security experts say firm should consider "pulling plug on servers" until flaws are fixed
Internet advertising firm DoubleClick has denied reports that the security of its Web servers has been compromised by vulnerabilities which lay unnoticed for the last two years.
French security site Kitetoa.com claims that a flaw with the doubleclick.net Web server, which runs Microsoft's IIS, means hackers had backdoor access to confidential data. DoubleClick denies this but admits it is undergoing a security audit after what it said were unsuccessful attacks by hackers last week.
According to Kitetoa, missconfigured Web servers at DoubleClick allowed the installation of a Trojan horse program on the firm's systems.
A screenshot published by Kitetoa appears to show the Web servers have been tampered with and that a file called eEyehack.exe uploaded onto its servers on April 29 1999. It points to an exploit first described by security consultants eEye Digital Security as the mechanism of the attack.
Network security consultant Paul Rogers, of MIS Corporate Defence, said there is no firm evidence eEye's exploit, which allows Trojans to be uploaded onto servers, was used against DoubleClick. The date of the file was before the publication of the eEye advisory and the size of the file, which might be a Trojan, does not correspond to any well known backdoor program.
Rogers said far firmer evidence that DoubleClick's servers are insecure is provided by another screenshot Kitetoe.com has obtained. This apparently shows username and passwords protecting DoubleClick's Abacus server, its market research division.
"If I was able to obtain this whilst doing an penetration test for one of my clients I'd advise them to pull the plugs on their boxes," said Rogers. "DoubleClick should consider running their services from a different platform whilst damaged host servers are repaired. It might also consider restricting access to services."
A spokeswoman for DoubleClick denied that its servers had been compromised for the last two years but admitted that it was in the process of conducting a full security audit after an attack by hackers last week. She stated that these attacks were unsuccessful.
In a statement on the attacks sent to The Register, DoubleClick said: "Over the last week there have been unsuccessful attempts made to hack into DoubleClick's servers. DoubleClick is now undergoing a comprehensive security audit, including the expertise of external security professionals and engineers, to fully ensure the continued integrity of our servers." ®