Security Experts:

C&C Flaw Offers Glimpse into Dridex Operations

Researchers have gained access to a command and control (C&C) panel of the Dridex banking malware, which has allowed them to determine how much information has been stolen by cybercriminals and how much money they might be making.

In January, experts at Buguroo, a threat intelligence startup and spinoff of Deloitte’s European Security Operations Center, came across what appeared to be a new and evolved Dridex campaign.

The threat has been using an automated transfer system (ATS) to deliver personalized webinjects and help attackers steal personal and financial information from victims. An analysis of the JavaScript code responsible for stealing banking credentials allowed researchers to determine the location of a C&C panel used by the malware’s operators.

A closer look at the panel revealed a vulnerability that allowed Buguroo to recover most of the data stolen in a Dridex campaign. The stolen records included account numbers, names, last login dates, card numbers, card types, and information on the issuing bank and country of origin.

Researchers recovered roughly 16.000 unique credit card records stolen from victims in more than 100 countries. While most of the data comes from European and English-speaking countries, the list of impacted regions also includes the Middle East, Africa and Latin America.

“Despite 70 percent of the stolen credit cards recovered being associated with English-speaking issuing organizations, around 85 percent of entities affected are located in non-English-speaking countries,” Buguroo said in its report.

Based on the number of compromised credit cards found in the C&C panel, Buguroo has calculated that attackers might have stolen as much as $800,000, even if they only obtained $500 from 10 percent of the 16,000 cards.

The vulnerable panel had been part of the 220 subnet, which was briefly disrupted last year when the Dridex botnet was targeted by law enforcement and security firms in Europe and the U.S.

A report published earlier this year by Symantec revealed that the 220 subnet was the most prolific, accounting for 40 percent of all 145 different Dridex spam campaigns seen by the security firm over a 10-week period. Buguroo estimates that cybercrooks could have made up to $20 million in that 10-week period assuming that they launched multiple campaigns.

In addition to distributing banking malware, Dridex operators have recently started using the botnet to deliver the Locky ransomware. Last month, Trustwave reported observing over 4 million spam emails sent out over a one-week period in an effort to distribute Locky.

Related: Macro Malware Dridex, Locky Using Forms to Hide Code

Related: Dridex Trojan Borrows Redirection Attack Scheme from Dyre Malware

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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.