Kaspersky Lab Discovers Chthonic: A New Strain of ZeuS Trojan Targeting Online Banks Worldwide

By   ISBuzz Team
Writer , Information Security Buzz | Dec 22, 2014 05:05 pm PST

Kaspersky Lab’s security analysts have detected a significant new malware threat targeting online banking systems and their customers. Identified as an evolution of the infamous ZeuS Trojan, Trojan-Banker.Win32.Chthonic, or ‘Chthonic’ for short, is known to have hit over 150 different banks and 20 payment systems in 15 countries. It appears to be mainly targeting financial institutions in the UK, Spain, the US, Russia, Japan, and Italy.

Chthonic exploits computer functions including the web camera and keyboard to steal online banking credentials such as saved passwords. Attackers can also connect to the computer remotely and command it to carry out transactions.

Chthonic’s main weapon, however, is web injectors. These enable the Trojan to insert its own code and images into the bank pages loaded by the computer’s browser, allowing the attackers to obtain the victim’s phone number, one-time passwords and PINs, as well as any login and password details entered by the user.

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Victims are infected through web links or by email attachments carrying a .DOC extension that then establishes a backdoor for malicious code. The attachment contains a specially crafted RTF document designed to exploit the CVE-2014-1761 vulnerability in Microsoft Office products.

Once downloaded, malicious code that contains an encrypted configuration file is injected into the msiexec.exe process and a number of malicious modules are installed on the machine.

So far Kaspersky Lab has discovered modules that can collect system information, steal saved passwords, log keystrokes, enable remote access, and record video and sound through the web camera and microphone, if present.

In the case of one of the Japanese banks targeted, the malware was able to hide the bank’s warnings and instead inject a script that allows the attackers to carry out various transactions using the victim’s account.

Affected customers of Russian banks are greeted by completely fraudulent banking pages as soon as they log on. This is achieved by the Trojan creating an iframe with a phishing copy of the website that has the same size as the original window.

Chthonic shares some similarities with other Trojans.  It uses the same encryptor and downloader as Andromeda bots, the same encryption scheme as Zeus AES and Zeus V2 Trojans, and a virtual machine similar to that used in ZeusVM and KINS malware.

Fortunately, many code fragments used by Chthonic to perform web injections can no longer be used because banks have changed the structure of their pages and in some cases the domains as well.

“The discovery of Chthonic confirms that the ZeuS Trojan is still actively evolving,” said Yury Namestnikov, Senior Malware Analyst at Kaspersky Lab and one of the researchers who worked on the investigation of the threat. “Malware writers are making full use of the latest techniques, helped considerably by the leak of the ZeuS source code. Chthonic is the next phase in the evolution of ZeuS. It uses Zeus AES encryption, a virtual machine similar to that used by ZeusVM and KINS, and the Andromeda downloader to target financial institutions and innocent customers in ever more sophisticated ways. We believe that we will undoubtedly see new variants of ZeuS in the future and will continue to track and analyse every threat to stay one step ahead of the cybercriminals.”

For more details, please go to Securelist.

About Kaspersky Lab

Kaspersky LabKaspersky Lab is the world’s largest privately held vendor of endpoint protection solutions. The company is ranked among the world’s top four vendors of security solutions for endpoint users*. Throughout its more than 17-year history Kaspersky Lab has remained an innovator in IT security and provides effective digital security solutions for large enterprises, SMBs and consumers. Kaspersky Lab, with its holding company registered in the United Kingdom, currently operates in almost 200 countries and territories across the globe, providing protection for over 300 million users worldwide. Learn more at http://www.kaspersky.co.uk.