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

2/1/2010
02:50 PM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%

Botnet Floods Major Websites With Fake SSL Connections

DDoS-like traffic surge against CIA, Chase, Google Chrome, FBI, and others has researchers puzzled by Pushdo botnet's plans

A spamming botnet known for keeping a low profile has been hammering hundreds of Websites -- including the CIA, Chase, Mozilla Labs, Twitter, SANS, Google Chrome, and the FBI -- during the past week with an unusually conspicuous amount of phony traffic that has researchers rushing to analyze its next move.

The Pushdo botnet, a.k.a. "Cutwail" and "Pandex," has been flooding those sites with bogus SSL connections that stop short of requesting anything from the Website. The infected bots begin to initiate an SSL connection with some "junk" traffic and then disconnect, according to The Shadowserver Foundation. Shadowserver and other researchers have been monitoring the activity, which increased traffic by several million hits across several hundred thousand IP addresses, according to Shadowserver.

The botnet hit the ZeusTracker Website, for example, with hundreds of thousands of different IP addresses within a 24-hour period. "This is a lot of bots generating a lot of traffic," blogged Steven Adair, a researcher with Shadowserver. Recent code changes to Pushdo resulted in its bots generating the "junk" SSL connections to the 315 Websites, he said.

So what is Pushdo up to? Joe Stewart, director of malware research for Secureworks, says the botnet is making fake SSL connection attempts: Malformed packets cause the server to return an SSL negotiation error. "By adding the initial header of an SSL conversation, they may be attempting to avoid closer scrutiny by less vigilant inspection devices," Stewart says. "And by sending a flurry of these connections to a number of legit 'decoy' sites, it helps the Pushdo C&C [command and control] traffic blend in and remain undetected in some cases," he says.

It's unclear thus far whether this is a test-run for phony SSL connections gone amuck that ended up exposing this Pushdo traffic, or something else. Stewart says it's possible there could be more to the latest activity, such as the botnet's rotating its target lists. "It's hard to say," he says.

Blending in has traditionally been Pushdo's trademark: Although it's one of the top five spamming botnets, it's also one of the more under-the-radar botnets around. But this latest activity has researchers wondering how this massive surge of traffic, which resembles a distributed denial-of-service (DDoS) attack, would ultimately help its traffic blend in and become less detectable.

Shadowserver says the traffic is technically an attack, even though it doesn't appear to be trying to knock the sites offline like a DDoS does. "We find it hard to believe this much activity would be used to make the bots blend in with normal traffic, but at the same time it doesn't quite look like a DDoS either," Adair says.

Secureworks' Stewart says he has witnessed botnets sending traffic via SSL or port 443, but this phony SSL connection attempt is a first. "The Pushdo C&C protocol now also uses similar packets to encapsulate its encrypted/compressed phone-home requests," he says. "Port 443 is commonly being used to proxy all kinds of non-SSL traffic by legit applications and bots alike, so it stands to reason that a heuristic one might look for suspicious or firewall-policy-violating traffic connections over port 443 that aren't using SSL. "

The surge in traffic from Pushdo could cause problems for Websites with limited bandwidth and that typically get only a few hundred to a few thousand hits daily, Shadowserver says.

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

Kelly Jackson Higgins is the Executive Editor of Dark Reading. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Sodinokibi Ransomware: Where Attackers' Money Goes
Kelly Sheridan, Staff Editor, Dark Reading,  10/15/2019
Data Privacy Protections for the Most Vulnerable -- Children
Dimitri Sirota, Founder & CEO of BigID,  10/17/2019
7 SMB Security Tips That Will Keep Your Company Safe
Steve Zurier, Contributing Writer,  10/11/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Write a Caption, Win a Starbucks Card! Click Here
Latest Comment: The old using of sock puppets for Shoulder Surfing technique. 
Current Issue
7 Threats & Disruptive Forces Changing the Face of Cybersecurity
This Dark Reading Tech Digest gives an in-depth look at the biggest emerging threats and disruptive forces that are changing the face of cybersecurity today.
Flash Poll
2019 Online Malware and Threats
2019 Online Malware and Threats
As cyberattacks become more frequent and more sophisticated, enterprise security teams are under unprecedented pressure to respond. Is your organization ready?
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-8216
PUBLISHED: 2019-10-17
Adobe Acrobat and Reader versions , 2019.012.20040 and earlier, 2017.011.30148 and earlier, 2017.011.30148 and earlier, 2015.006.30503 and earlier, and 2015.006.30503 and earlier have an out-of-bounds read vulnerability. Successful exploitation could lead to information disclosure .
CVE-2019-8217
PUBLISHED: 2019-10-17
Adobe Acrobat and Reader versions , 2019.012.20040 and earlier, 2017.011.30148 and earlier, 2017.011.30148 and earlier, 2015.006.30503 and earlier, and 2015.006.30503 and earlier have an use after free vulnerability. Successful exploitation could lead to arbitrary code execution .
CVE-2019-8218
PUBLISHED: 2019-10-17
Adobe Acrobat and Reader versions , 2019.012.20040 and earlier, 2017.011.30148 and earlier, 2017.011.30148 and earlier, 2015.006.30503 and earlier, and 2015.006.30503 and earlier have an out-of-bounds read vulnerability. Successful exploitation could lead to information disclosure .
CVE-2019-8219
PUBLISHED: 2019-10-17
Adobe Acrobat and Reader versions , 2019.012.20040 and earlier, 2017.011.30148 and earlier, 2017.011.30148 and earlier, 2015.006.30503 and earlier, and 2015.006.30503 and earlier have an use after free vulnerability. Successful exploitation could lead to arbitrary code execution .
CVE-2019-8220
PUBLISHED: 2019-10-17
Adobe Acrobat and Reader versions, 2019.012.20040 and earlier, 2017.011.30148 and earlier, 2017.011.30148 and earlier, 2015.006.30503 and earlier, and 2015.006.30503 and earlier have an use after free vulnerability. Successful exploitation could lead to arbitrary code execution .