Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Attacks/Breaches

'Fort Disco' Botnet Behind Attack Campaign Against Thousands Of Sites

A 25,000-PC strong botnet is behind a brute force campaign that has compromised more than 6,000 websites

Researchers at Arbor Networks have uncovered a crafty attack campaign that has compromised thousands of sites powered by Joomla, WordPress, and Datalife Engine.

According to Arbor Networks, more than 6,000 sites have been compromised in a spate of brute force attacks launched by a botnet dubbed Fort Disco. Made up of more than 25,000 PCs, the botnet receives a list of sites to attack from a central command and control server. On some of the sites, a variant of the "FilesMan" PHP backdoor is installed by the attackers.

"By uploading a PHP shell to compromised sites, an attacker can easily issue commands to thousands of compromised sites in seconds," Matt Bing, a research analyst at Arbor Networks' ASERT team, notes in a blog post. "Blogs and CMSs tend to be hosted in data centers with immense network bandwidth. Compromising multiple sites gives the attacker access to their combined bandwidth, much more powerful than a similarly sized botnet of home computers with limited network access by comparison."

In a handful of cases, researchers found drive-by exploit kit tools, but we have no evidence the attacker actually used them to target visitors to the compromised sites, Bing tells Dark Reading. In particular, some of the sites contained a PHP-based redirector that sent Windows users running Internet Explorer, Firefox, or Opera to a series of sites before ultimately landing on one with the Styx exploit kit.

There are at least four variants of the malware used in the attack. Once on an infected system, the malware receives commands from the attacker that include a URL of a list of sites to attack. According to Arbor Networks, the target list can be anywhere from 5,000 to 10,000 sites at a time. Included in the commands is the password to use or a URL to a password list. The malware also has a URL of usernames hardcoded, and will attempt to login to the sites with combinations of the usernames and passwords.

The most common password was "admin," which worked 893 times. The next most popular was "123456," which worked on 588 of the compromised sites.

"The number of weak passwords is not surprising, as this campaign is clearly a target of opportunity and not focused on a specific target," Bing says. "This is interesting as it marks a sea change in the tactics of attackers. In addition to drive-by exploits of unpatched Windows machines being the low-hanging fruit, attackers are learning that these blog and content management systems are often vulnerable to trivial attacks."

The attackers behind the campaign are believed by Arbor Networks to be from a post-Soviet state due to the fact that the majority of the sites being targeted are in Russia or the Ukraine, as are all of the command and control sites. In addition, a Russian error string was found on several command and control sites.

The top three countries in terms of infections are the Philippines, Peru, and Mexico.

"Beginning with the Brobot attacks in early 2013, we’ve seen attackers focusing on targeting blogs and content management systems," Bing blogs. "This marks a tactical change in exploiting weak passwords and out-of-date software on popular platforms."

"While we have no evidence the Fort Disco campaign is related to Brobot or denial-of-service activity, we’ve experienced the threat that a large blog botnet can deliver," he writes.

Have a comment on this story? Please click "Add Your Comment" below. If you'd like to contact Dark Reading's editors directly, send us a message.

Brian Prince is a freelance writer for a number of IT security-focused publications. Prior to becoming a freelance reporter, he worked at eWEEK for five years covering not only security, but also a variety of other subjects in the tech industry. Before that, he worked as a ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
News
Inside the Ransomware Campaigns Targeting Exchange Servers
Kelly Sheridan, Staff Editor, Dark Reading,  4/2/2021
Commentary
Beyond MITRE ATT&CK: The Case for a New Cyber Kill Chain
Rik Turner, Principal Analyst, Infrastructure Solutions, Omdia,  3/30/2021
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
2021 Top Enterprise IT Trends
We've identified the key trends that are poised to impact the IT landscape in 2021. Find out why they're important and how they will affect you today!
Flash Poll
How Enterprises are Developing Secure Applications
How Enterprises are Developing Secure Applications
Recent breaches of third-party apps are driving many organizations to think harder about the security of their off-the-shelf software as they continue to move left in secure software development practices.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2021-30485
PUBLISHED: 2021-04-11
An issue was discovered in libezxml.a in ezXML 0.8.6. The function ezxml_internal_dtd(), while parsing a crafted XML file, performs incorrect memory handling, leading to a NULL pointer dereference while running strcmp() on a NULL pointer.
CVE-2021-30481
PUBLISHED: 2021-04-10
Valve Steam through 2021-04-10, when a Source engine game is installed, allows remote authenticated users to execute arbitrary code because of a buffer overflow that occurs for a Steam invite after one click.
CVE-2021-20020
PUBLISHED: 2021-04-10
A command execution vulnerability in SonicWall GMS 9.3 allows a remote unauthenticated attacker to locally escalate privilege to root.
CVE-2021-30480
PUBLISHED: 2021-04-09
Zoom Chat through 2021-04-09 on Windows and macOS allows certain remote authenticated attackers to execute arbitrary code without user interaction. An attacker must be within the same organization, or an external party who has been accepted as a contact. NOTE: this is specific to the Zoom Chat softw...
CVE-2021-21194
PUBLISHED: 2021-04-09
Use after free in screen sharing in Google Chrome prior to 89.0.4389.114 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.