VBA Macro Malware Jumping on the Ransomware Bandwagon

Macro malware made a comeback late last year. Then, in February of this year, researchers discovered a Neutrino bot dropper that uses Visual Basic for Applications (VBA) macros to deliver its malicious payload. IBM Managed Security Services found even more notable activity associated with macro malware in the last two months. This activity is interesting because, as Dynamoo’s Blog reported, the attachment is a variant of Locky ransomware.

VBA Malware Attack Origins

The top 50 VBA malware-sending IPs — of literally thousands of malicious IPs — are those with the largest number of targets. These are broken down into 15 VBA spam malware-sending countries.

The country with the greatest number of malicious IPs in the top 50 is Turkey, with 13. India is in second place with nine malicious IPs. These findings come as no surprise: As of Sept. 6, 2016, these countries held eighth and fourth place, respectively, in list of top 10 countries with outgoing malicious internet activity, according to Country IP Blocks.

The IP most active in sending VBA spam malware, in terms of both the greatest number of targets and security events, is 103.255.5.117. It’s located in Pakistan, which topped Microsoft’s “Malware Infection Index 2016.” IBM X-Force Exchange assigned the IP a risk rating of 10, the highest level of risk.

Infected machines, or bots, are often used to relay spam. This may or may not be the case with this particular IP, but it is interesting that seven of the VBA spam malware countries below were also among the most vulnerable to malware threats. All IPs in the top 50 currently have a risk rating of 10.

bubble chart of the top origins of attack for VBA malware

Top origins of VBA malware based on top 50 IPs (July 1, 2016, to Sept. 6, 2016). Source: IBM Managed Security Services.

Gone Phishing

Although the “from” field has a few variations, the majority of the malicious spam email observed by IBM MSS appeared to come from two different emails: emmacritchley@advantage-finance.co.uk and jen@purple-office.com. The malware spam had a DOCM file attached. The file names also varied greatly from email to email.

Per usual, the initial attack vector is a phishing email. Its parting gift, if it’s successful? Ransomware.

Reel In Phishing Attempts

Educating employees about phishing and its associated risks continues to be paramount. A variety of approaches can be used, including videos, online phishing tests, webinars and in-person instruction. Employers should require training at regular intervals.

Employee education should include these main points:

  • Most companies, banks and agencies never request personal information via email. Don’t fall prey to this most common type of phishing.
  • If you suspect an email might be a spear phishing campaign within your company, report it.
  • Immediately suspect emails with generic greetings, like “Dear Customer,” or spelling and grammatical errors.
  • Never reveal personal or financial information in response to an email request, no matter who appears to have sent it.

Education is important, but cannot stand alone. Network protection backed by comprehensive global threat intelligence is key.

The aforementioned VBA malware attack attempts were detected by IBM signatures. These signatures look for suspicious VBA macros within a document. Ensure signatures that detect VBA malware are enabled in your environment.

Ransomware Response

The phish got past your educated user. It got past your network defense. Now, you need to be prepared to respond to the ransomware infection.

IBM recently published its “Ransomware Response Guide,” which prepares an organization for the types of events and incidents it is likely to encounter. It also provides guidance once an incident has occurred, including analysis, containment, eradication, recovery and post-incident activity.

The moral of the story: Don’t trust email attachments, even if they come from a trusted source. Unless you’re expecting an email with a document attached, call the sender and confirm its legitimacy. The computer might have been compromised and commandeered to send emails without senders’ knowledge, or their email addresses could have been spoofed.

Download the complete Ransomware Response Guide from IBM Incident Response Services

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Michelle Alvarez

Threat Researcher and Editor, IBM Managed Security Services

Michelle Alvarez is a Threat Researcher and Editor for IBM's Managed Security Services; she brings more than 10 years of industry experience to her role. In this role she focuses communications efforts around threat research and mitigation. Michelle joined IBM through the Internet Security Services (ISS) acquisition, where she served as an Analyst on the X-Force Vulnerability Database Team.