Pierluigi Paganini April 07, 2016

A threat actor named TA530 group, has been targeting executives in an attempt to infect their machine with various malware, including ransomware.

Ransomware continues to represent one of the greatest threat for the Internet users, the FBI recently issued a confidential urgent “Flash” message to the businesses and organizations about the Samsam Ransomware.

Security firms are assisting to a rapid increase in the number of infections caused by the ransomware, US and Canada issued a joint warning about the recent surge in ransomware-based attacks. The most disconcerting aspect of the situation is the continuous improvement of such kind of malware and the techniques adopted by criminal organizations to spread it.

Today we will discuss a new threat that adopts a singular strategy to infect the victims, it relies on spear-phishing attacks to compromise users’machines.

Security firms use to observe spear-phishing attacks for espionage purposes, however, the adoption of these techniques in the criminal field contributes increasing their effectiveness.

In a spear-phishing attack, threat actors use a deep knowledge of the potential victims to target them, clearly this approach allows them to tailor the operation.

According to security experts at Proofpoint, a threat actor, named TA530 group, has been targeting executives and other high-level employees in an attempt to compromise their machine with various malware, including the CryptoWall ransomware.

Other threats in the malware arsenal of the TA530 are:

• Ursnif ISFB – banking Trojan configured to target Australian banks
• Fileless Ursnif/RecoLoad – Point of Sale (PoS) reconnaissance Trojan targeted at Retail and Hospitality. It was first featured in Kafeine’s blog [1] in July of 2015,  which suggests that it has been in distribution since 2014; shortly after, it was described with more detail by Trend Micro [2].
• Tiny Loader – a downloader used in campaigns targeting Retail and Hospitality verticals. We have not observed it download secondary payloads, but previously it has been used to download malware such as AbaddonPOS [3].
• TeamSpy/TVSpy – RAT utilizing Teamviewer [4], primarily targeted at Retail and Hospitality
• CryptoWall – File encrypting ransomware targeted at a variety of companies
• Nymaim – Installs a banking Trojan [5] primarily targeted at Financial companies
• Dridex Botnet 222 – banking Trojan botnet with UK targeting. Proofpoint first observed this botnet when it was dropped by Bedep in January 2016 [6]

The attackers were able to profile victims, targeting specific industries and geographic areas.

The approach is simple, targeting executives there is a high likelihood that victims will pay to restore high-value information and usually people in these positions are more likely to have access to corporate online bank accounts and other online services.

“Additionally, TA530 customizes TA530 customizes the e-mail to each target by specifying the target’s name, job title, phone number, and company name in the email body, subject, and attachment names. On several occasions, we verified that these details are correct for the intended victim. While we do not know for sure the source of these details, they frequently appear on public websites, such as LinkedIn or the company’s own website. The customization doesn’t end with the lure; the malware used in the campaigns is also targeted by region and vertical.” states the blog post published Tuesday

The TA530 group targets tens of thousands of recipients in US, UK, and Australian organizations, the figures are very interesting if we consider that are related to spear-phishing attacks.

“We observed TA530 at times targeting only a specific and narrow vertical, such as Retail and Hospitality. At other times, the campaigns appear more widespread. Overall, the volume of messages targeting each vertical is shown below:

“Based on what we have seen in these examples from TA530, we expect this actor to continue to use personalization and to diversify payloads and delivery methods,” states ProofPoint. “The personalization of email messages is not new, but this actor seems to have incorporated and automated a high level of personalization, previously not seen at this scale, in their spam campaigns.”

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Pierluigi Paganini

(Security Affairs – Ransomware, TA530 group)