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Russian Hackers Infected 1 Million Phones With Banking Trojan

Russia Dismantles Major Cybercrime Operation Targeting Bank Accounts via Android Malware

The Russian Interior Ministry announced on Monday that authorities dismantled a major cybercrime gang that had stolen nearly $900,000 from bank accounts after infecting more than one million Android smartphones with a Trojan.

Authorities said they identified 20 suspects in Moscow and five other regions of Russia. They believe the group was led by a 30-year-old living in the city of Ivanovo.

Group-IB, the Russian cybersecurity firm that assisted the government’s investigation, reported that 16 members of the group were detained in November 2016, while the last active member was apprehended in April.

The group used an Android banking Trojan dubbed “Cron,” which researchers first spotted in March 2015, when cybercriminals had been distributing it disguised as Viber and Google Play apps.

Roughly one year later, experts noticed that someone had offered to rent an Android banking Trojan dubbed “Cron Bot.” In an analysis of the mobile malware market, IBM X-Force researchers reported in April 2016 that Cron Bot had been leased for between $4,000 and $7,000, depending on the package.

The cybercrime gang targeted by Russian authorities used spam SMS messages to deliver the Trojan to individuals in Russia. The messages informed recipients that their ads or photos had been posted on a website, and included links to a site that tricked users into downloading and installing the malware. The threat had been disguised as various apps, including Avito, Pornhub, Framaroot and Navitel.

Once it infected a device, the Trojan allowed the cybercrooks to steal and hide SMS messages coming from banks, and send SMSs to specified numbers. Since many Russian banks allow their customers to conduct transactions via SMS, these features allowed the fraudsters to transfer money from the victims’ accounts into their own.

According to Group-IB, the gang opened more than 6,000 bank accounts to which they transferred the stolen funds. Investigators said the Cron malware was used to steal an average of $100 (8,000 rubles) from 50-60 bank customers each day.

The cybercriminals managed to infect more than one million smartphones and stole nearly $900,000 (50 million rubles).

Following the success of their operation in Russia, the group decided to expand to other countries with the aid of a banking Trojan named Tiny.z, which they rented for $2,000 per month. Tiny.z uses overlay screens adapted to each targeted bank’s mobile application in order to trick victims into handing over personal and financial details that can be leveraged to steal money from their account.

The Cron gang had been planning on hitting France first, and they developed web injections for several of the country’s banks, including Credit Agricole, Assurance Banque, Banque Populaire, BNP Paribas, Boursorama, Caisse d'Epargne, Societe Generale and LCL. However, law enforcement managed to disrupt their operations before they could launch attacks on French banks.

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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.