Researchers exploit Conficker flaw to find infected PCs
Three researchers, including Dan Kaminsky, created a scanner to quickly detect worm on networks
Computerworld - Just days before the Conficker worm is set to contact its controllers for new instructions, security researchers have discovered a flaw in the worm that makes it much easier for users to detect infected PCs.
Tillmann Werner and Felix Leder, members of the Honeynet Project, an all-volunteer organization that monitors Internet threats, have discovered that Conficker-infected PCs return unusual errors when sent specially crafted remote procedure call (RPC) messages, according to preliminary information they have posted on the Web.
There's a growing urgency in the battle against Conficker as Wednesday approaches. PCs infected with Conficker.c, the third version of the worm, will use a new communication scheme starting April 1 to establish a link to the command-and-control servers operated by the hackers. What's troubling to researchers is that they have no clue as to what orders the worm's makers will give those machines.
Using their discovery, Werner and Leder, along with Dan Kaminsky, the security researcher who last summer uncovered a critical flaw in the Domain Name System software, spent the weekend crafting a scanner that lets users quickly sniff out Windows machines infected with the worm.
"You can literally ask a server if it's infected with Conficker, and it will tell you," Kaminsky said in an entry to his blog today.
The scanner, in turn, has been modified and added to enterprise-grade detection systems from companies such as McAfee, nCircle and Qualys, which plan to release updates today. The free open-source Nmap scanner is also slated to include the new detection capability.
"What Tillmann and Felix found was that Conficker systems react differently to certain RPC parameters," said Wolfgang Kandek, chief technology officer at Qualys Inc. "The difference is very subtle."
Conficker-patched machines answer differently to the special RPC messages because the worm, which exploited a Windows vulnerability that Microsoft Corp. patched last October, uses its own version of the Microsoft patch to effectively close the door behind it. Quashing a bug is a common tactic by malware authors to prevent other criminals from stealing their infected systems.
- Conficker's makers lose big, expert says
- Conficker activation passes quietly, but threat isn't over
- FAQ: Just the facts on Conficker
- Security managers concerned but confident about Conficker on eve of expected attack
- IBM: Conficker.c infects small number in U.S.
- Security software scammers riding on Conficker's coattails
- Researchers exploit Conficker flaw to find infected PCs
- Conficker's next move a mystery to researchers
- Mobile First: Securing Information Sprawl Learn how the partnership between Box and MobileIron can help you execute a "mobile first" strategy that manages and secures both mobile apps...
- Cybersecurity Imperatives: Reinvent your Network Security The Rise of CyberSecurity
- Surescripts Case Study- Securing Keys and Certificates Surescripts implemented Venafi's Trust Protection Platform™ to secure digital keys and certificates, ensure the privacy and confidentiality of electronic clinical information for its...
- Ponemon 2014 SSH Security Vulnerability Report According to research by the Ponemon Institute, 3 out of 4 enterprises have no security controls in place for SSH which leaves organizations...
- Responding to New SSL Cybersecurity Threat The featured Gartner research examines current strategies to address new SSL cybersecurity threats and vulnerabilities.
- Deep Dive into Advanced Networking and Security with Hybrid Cloud Security and networking are among the top concerns when moving workloads to the cloud. VMware vCloud® Hybrid Service™ enables you to extend your... All Security White Papers | Webcasts
Our new bimonthly Internet of Things newsletter helps you keep pace with the rapidly evolving technologies, trends and developments related to the IoT. Subscribe now and stay up to date!