US-CERT Warns Dyre Malware Used in Phishing Attacks

The Dyre malware is back to doing what it does well – targeting online bankers and stealing their user credentials in a new phishing campaign.

According to US-CERT (United States Computer Emergency Readiness Team), which is under the Department of Homeland Security, the malware is spreading via malicious PDF attachments that take advantage of unpatched versions of Adobe Reader. Specifically, the attackers are targeting CVE-2013-2729 and CVE-2010-0188.

“Since mid-October 2014, a phishing campaign has targeted a wide variety of recipients while employing the Dyre/Dyreza banking malware,” US-CERT noted in its advisory. “Elements of this phishing campaign vary from target to target including senders, attachments, exploits, themes, and payload(s). Although this campaign uses various tactics, the actor’s intent is to entice recipients into opening attachments and downloading malware.”

A system infected with Dyre banking malware will attempt to harvest credentials for online services, including banking services, the advisory said.

The emails associated with a campaign use the misspelled subject line “Unpaid invoic” as well as the attachment “Invoice621785.pdf.”

If the exploit is successful, the malware copies itself under C:Windows[RandomName].exe and creates a service named “Google Update Service” by setting the following registry keys:

• HKLMSYSTEMCurrentControlSetServicesgoogleupdateImagePath: “C:WINDOWSpfdOSwYjERDHrdV.exe”
• HKLMSYSTEMCurrentControlSetServicesgoogleupdateDisplayName: “Google Update Service”

The Dyre malware was first spotted by security researchers in June targeting large financial institutions around the world. Last month, the malware was observed going after user credentials for Salesforce.com.

“Historically, banking Trojans were used to steal account credentials of banking customers but now sensitive business data is being stolen from companies in the healthcare industry, retail, software industry and others,” Don Jackson, director of threat intelligence at PhishLabs, blogged recently. “Malicious software developers are seeking access to organizational systems and operating systems to steal data that would aid in identity theft for purposes of committing fraud. Attackers remain patient and persistent; evolving the tools, harvesting the data and attacking when it is unexpected.”

Recent enhancements to the malware include the use of certificates from a trusted Certificate Authority to encrypt command and control communications between the Trojan and its master server as well as a “browsersnapshot” feature that collects cookies as well as client-side certificates and private keys used by Internet Explorer and Firefox.  

According to US-CERT, users and administrators should follow basic security steps such as not clicking unsolicited links in email and being cautious when opening email attachments.