A Welsh government Web site has been hacked to serve up malicious JavaScript,
a sign that the spate of attacks first spotted last month are continuing, analysts
from security vendor Sophos warned Friday.

The method of attack is similar to one that recently victimized pages within
Trend Micro's Web site, said Graham Cluley, senior technology consultant for
Sophos.

Trend Micro's Web site was one of up to 20,000 sites discovered in mid-March
where hackers found a weakness in the server's security that allowed them to
implant malicious JavaScript.

If a user visits an infected page, the JavaScript initiates a download of malicious
code from another server. Sophos named the attack Troj/Badsrc-A.

In this particular case, the server that is hosting the malicious code is down,
Cluley said. One possibility is that the server exceeded its allowed bandwidth
due to a high number of downloads of malicious code, which would indicate that
many people could be infected, Cluley said.

Hacked Web sites are increasingly being used to infect PCs with malicious software.
The attack method can be used to infect fully patched computers. Once the bad
JavaScript runs, a user could be prompted to download a piece of software, which
the victim may believe they need in order to access the legitimate Web site,
but the software is actually harmful.

In other cases, the JavaScript could launch an attack that seeks to exploit
vulnerabilities in, for example, QuickTime, Cluley said. Earlier this week,
Apple issued 11 patches for its media player. JavaScript could launch QuickTime,
and if the application isn't patched, the PC could be infected.

The Welsh site is one of hundreds upon hundreds of sites that Sophos has catalogued
as infected. The vendor chose to publicize its findings on the Welsh site to
make a point about how seemingly legitimate sites are being affected by this
latest round of attacks, Cluley said.

Absent using security software, one sure-fire way to block this kind of attack
is by using the Firefox browser with the NoScript
extension. NoScript blocks the execution of JavaScript, Java and Flash in
the browser, which hackers are using to get into machines.

NoScript hampers the function of legitimate Web sites using JavaScript and
those plugins, but users have the option of white listing safe sites. The extension,
as well as Firefox, are free. In the case of the Welsh Web site, NoScript would
block the attack, Cluley said.

Sophos has contacted the organization responsible for the Web site but has
yet to receive a response, he said.

IDG News Service

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