Russian Hackers Exploited Windows Flaws in Attacks on European Firms

Financially-motivated hackers believed to be operating out of Russia recently targeted companies in Western Europe, and the attacks apparently involved a combination of two Windows vulnerabilities that Microsoft did not expect to be exploited.

According to Singapore-based cybersecurity firm Group-IB, the threat groups tracked as TA505 (aka Evil Corp) and Silence — the company previously found links between the two groups — targeted at least two pharmaceutical and manufacturing companies in Belgium and Germany in late January.

The attacks have been attributed to Silence and TA505 based on the used tools, but it’s possible that only one of them was involved.

Analysis of the infrastructure used by the hackers led to the discovery of an executable named comahawk.exe that incorporated two local privilege escalation exploits targeting Windows.

The vulnerabilities, tracked as CVE-2019-1405 and CVE-2019-1322, were patched by Microsoft in November 2019 and October 2019, respectively. Microsoft’s advisories for both these flaws say “exploitation [is] less likely”

In mid-November 2019, NCC Group, whose researchers reported the vulnerabilities to Microsoft, published a blog post describing the weaknesses. Shortly after, someone made public an exploit named COMahawk that weaponizes CVE-2019-1405 and CVE-2019-1322.

Group-IB researchers uncovered this exploit on the attacker’ servers and they believe it was likely deployed in the campaign targeting European companies.

TA505 has used several pieces of malware in its operations, including the Dridex banking trojan and the Locky ransomware. Group-IB believes that the German and Belgian companies may have been targeted either with ransomware or as part of a “complex supply-chain attack.”

Earlier this month, cybersecurity firm Prevailion published a report detailing attacks launched by TA505 against German companies. The attacks involved trojanized resumes sent to the human resources department at targeted businesses.

A report published in August 2019 by Group-IB revealed that the Silence group had stolen roughly $3.5 million since September 2018. Silence had targeted banks in over 30 countries across Europe, Latin America, Africa, and Asia.

If Silence was involved in the recent attacks on pharmaceutical and manufacturing companies, it could indicate a shift in their strategy, Group-IB said.

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