Security Experts:

Citadel Trojan Targets Password Managers, Authentication Solutions

A new variant of the notorious information-stealing malware Citadel captures keystrokes in an effort to obtain the passwords that protect access to authentications solutions and password managers, IBM Trusteer reported on Wednesday.

According to researchers, cybercriminals are using a new configuration file that instructs the Trojan to monitor processes associated with neXus Personal Security Client (Personal.exe), Password Safe (PWsafe.exe), and KeePass (KeePass.exe). When the malware detects that one of these processes is running, it activates its keylogging functionality.

IBM hasn't been able to determine if the attack is targeted or opportunistic. The company identified this new type of Citadel configuration file on a computer with IBM Trusteer Apex installed on it.

"This machine can be located anywhere in the world and used by any type of user, such as a consumer using Web services, an enterprise employee using corporate systems, a contractor that works with other organizations — we cannot know," Dana Tamir, Director of Enterprise Security at Trusteer, explained in a blog post. "The machine was already infected by Citadel when IBM Trusteer Apex was installed on it. Therefore, it is unknown exactly how it became infected."

Researchers analyzed the configuration file and determined that a legitimate Web server had been used for command and control (C&C), but the cybercriminals had already removed their files from the machine by the time the investigation was conducted.

"Because the configuration file instructs the malware to capture keystrokes related to widely used password management and authentication solutions, we can’t know who, exactly, is the target of the attack. It might be an opportunistic attack, where the attackers are trying to see which type of information they can expose through this configuration, or a more targeted attack in which the attackers know that the target is using these specific solutions," Tamir said.

The targeted applications are highly popular. neXus Personal Security Client is an authentication solution that is used to conduct financial transactions, e-commerce and other sensitive activities in a secure manner directly from the desktop. Password Safe and KeePass are free, open-source password managers that securely store users' login credentials. By obtaining the master passwords to these apps, the attackers can gain access to the entire credentials database.

IBM says it has notified the companies whose products are targeted to allow them to alert their customers.

In September, IBM Trusteer researchers reported uncovering attacks in which Citadel had been used to target petrochemical organizations in the Middle East.

There are still numerous people who use passwords that are easy to guess or crack, but the recent data leaks have been an incentive for many Internauts and organizations to turn to password managers. The fact that cybercriminals are increasingly targeting these password managers is not surprising, considering that they are always adapting their tactics.

Many predict that passwords will soon become a thing of the past, being replaced with biometric authentication solutions. In the meantime, experts recommend the use of two-factor authentication and advanced malware protection solutions that can identify and block even the most sophisticated pieces of malware.

 

view counter
Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.