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

1/17/2008
07:45 AM
Connect Directly
Twitter
RSS
E-Mail
50%
50%

Attackers Use New 'Call-Home' Method to Infiltrate Home Networks

Honeynet Project researchers witness stealthy new method of botnet communication

Now the bad guys have discovered a way to set up a stealthy, continuous connection between the machines they infect and their own command and control servers.

Researchers with the Honeynet Project have been studying a new method being used by botnet operators and other cyber criminals that sets up what's called a "reverse tunnel proxy" connection -- a connection through the victim's Network Address Translation (NAT)-based filtering device such as a home router or other router or firewall.

What makes this approach different from traditional botnet relationships is that the command and control machine doesn't rely on the bot to "check in" and get its latest instructions, so it's more of a continuous connection, says Ralph Logan, a member of the board for the Honeypot Project and its chief public relations officer.

"The bot and the C&C don't need to maintain a connection for reconfiguration, 're-tooling,' or retasking," says Logan, who is also principal with The Logan Group. "They've created a new way to bypass any kind of routing device that gives you private IP addresses behind it."

The Honeynet Project, which will publish these findings next week in the latest in its series of "Know Your Enemy" white papers -- called "Know Your Enemy Lite: Proxy Threats - Socks v666" -- says the reverse tunnel proxy botnet is different from the classic IRC-based approach because it sets up dedicated proxies inside the victim's network from which controllers can initiate connection requests. A traditional bot initiates its connection via IRC, HTTP, or a peer-to-peer connection, waits for a command, and then follows the orders on behalf of the C&C machine.

Although home routers are the obvious mark, Logan says the technique could also be used against corporate networks as well.

An underlying weakness here is the common misperception that NAT protects users against direct attacks by assigning private and non-routable IP addresses that attackers can’t "see." And attackers are abusing these systems, which typically aren't properly secured, according to the researchers.

First the client machine gets infected by downloading a Trojan in an email attachment or by visiting a malicious Website. Then the attacker can have a connection "hiding in plain sight," according to the Honeynet Project report. And the proxy can also bypass IDS detection.

The Honeynet Project researchers say they have seen bad guys using this reverse tunnel proxy technique for relaying millions of spam messages worldwide, and that there's even an underground market for proxy abuse and collection. Another benefit for the bad guys: The bots could be mistakenly identified as the source of an attack.

Aside from spam, the reverse tunnel proxy is also being used for executing Web exploits and for targeted attacks, according to the Honeynet Project. The researchers say several criminal networks are currently using this technique. The report also includes mitigation strategies for network providers, including using security tools such as Snort, IPS, blacklisting, restricting outbound email, and adding various security policies.

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.

  • Honeynet Project

    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
    News
    A Startup With NSA Roots Wants Silently Disarming Cyberattacks on the Wire to Become the Norm
    Kelly Jackson Higgins, Executive Editor at Dark Reading,  5/11/2021
    Edge-DRsplash-10-edge-articles
    Cybersecurity: What Is Truly Essential?
    Joshua Goldfarb, Director of Product Management at F5,  5/12/2021
    Commentary
    3 Cybersecurity Myths to Bust
    Etay Maor, Sr. Director Security Strategy at Cato Networks,  5/11/2021
    Register for Dark Reading Newsletters
    White Papers
    Video
    Cartoon Contest
    Write a Caption, Win an Amazon Gift Card! Click Here
    Latest Comment: Google Maps is taking "interactive" to a whole new level!
    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-2020-18194
    PUBLISHED: 2021-05-17
    Cross Site Scripting (XSS) in emlog v6.0.0 allows remote attackers to execute arbitrary code by adding a crafted script as a link to a new blog post.
    CVE-2020-18195
    PUBLISHED: 2021-05-17
    Cross Site Request Forgery (CSRF) in Pluck CMS v4.7.9 allows remote attackers to execute arbitrary code and delete a specific article via the component " /admin.php?action=page."
    CVE-2020-18198
    PUBLISHED: 2021-05-17
    Cross Site Request Forgery (CSRF) in Pluck CMS v4.7.9 allows remote attackers to execute arbitrary code and delete specific images via the component " /admin.php?action=images."
    CVE-2020-21831
    PUBLISHED: 2021-05-17
    A heap based buffer overflow vulnerability exists in GNU LibreDWG 0.10 via read_2004_section_handles ../../src/decode.c:2637.
    CVE-2020-21842
    PUBLISHED: 2021-05-17
    A heap based buffer overflow vulnerability exists in GNU LibreDWG 0.10 via read_2004_section_revhistory ../../src/decode.c:3051.