Thousands of WordPress sites sucked into BlackHole

By Darren Pauli on Nov 2, 2011 9:03 AM
Filed under Security

Exploits aging TimThumb vulnerability.

Researchers have discovered a spike in malware infecting thousands of WordPress web sites that use a popular image tool.

The attacks came to light after French media outlet the Poitou-Charentes Journal began hosting on malware on its WordPress site.

Avast senior researcher Jan Sirmer found attackers had exploited weak FTP server authentication credentials and a vulnerability in the TimThumb image resizer to upload malicious PHP files to the site.

The attack used the BlackHole exploit kit which redirected the web site's visitors to an external malware-hosting site.

An additional 3500 unique infected Word Press sites were detected by Avast redirecting visitors to malicious sites between August 28 – 31. During September it blocked redirects from 2515 WordPress sites, Sirmer said.

In total, some 151,000 users had been hit with the malicious redirect from other compromised WordPress sites.

"I expect October results will be similar,” Sirmer said.

“The Poitou-Charentes Journal is just one part of a much bigger attack. These compromised sites are part of a network which redirected vulnerable users to sites distributing an array of malware.”

The vulnerability in the TimThumb resizer identified in August exists in the way the tool fetches images from websites like Flickr and Photobucket.

The utility runs only a partial check on hostnames meaning hackers could upload and execute arbitrary php code in the .php cache directory.

Sirmer recommended WordPress sites employ strong login credentials. A fix was available for the TimThumb tool.

 
Follow us on Facebook and Twitter
 

Copyright © SC Magazine, Australia

Thousands of WordPress sites sucked into BlackHole
 
 
 
 
 
Top Stories
Small reseller called in to fix mess Telstra left behind
Acurus rescues client that used to be telco's promotional case study.
 
The richest of the rich: top 10 tech billionaires
Who passed Michael Dell and founders of Google on Bloomberg's rankings?
 
How to wring money out of thin air
Cloud software and services have created a wi-fi monster.
 
Sign up to receive CRN email bulletins
   FOLLOW US...
Polls
My business strategy is to:

Latest Comments
CRN Magazine

Issue: 330 | August 2014

CRN Magazine looks in-depth at the emerging issues and developments for the channel, and provides insight, analysis and strategic information to help resellers better run their businesses.