The Gamaredon threat group has built a post-compromise tool arsenal that includes remote template injectors for Word and Excel documents as well as a unique Outlook mass-mailing macro, researchers recently discovered.
The tools, previously undocumented, boast a VBA macro aimed at Outlook that sends spearphishing emails to a victim’s Microsoft address book contacts, according to ESET researchers. Noting that the Gamaredon-linked tools were “detected as variants of MSIL/Pterodo, Win32/Pterodo or Win64/Pterodo,” ESET said in a blog post that the threat group, known for attacks mostly against Ukrainian organizations, has upped its activities “with constant waves of malicious emails hitting their targets’ mailboxes.”
The VBA employs a bundle of malicious code starting with a VBScript that kills the Outlook process then changes registry values to remove security around VBA macro execution in Outlook. The malicious OTM file containing a macro, the malicious email attachment and, sometimes, a list of recipients for the email are saved to disk. Once Outlook is relaunched with a special option that loads the Gamaredon VBA project, and after the Application.Startup event is received, malicious code is executed, sending malicious email to either everyone in a victim’s address book or within an organization or to predefined targets.
Please register to continue.
Already registered? Log in.
Once you register, you'll receive:
The context and insight you need to stay abreast of the most important developments in cybersecurity. CISO and practitioner perspectives; strategy and tactics; solutions and innovation; policy and regulation.
Unlimited access to nearly 20 years of SC Media industry analysis and news-you-can-use.
SC Media’s essential morning briefing for cybersecurity professionals.
One-click access to our extensive program of virtual events, with convenient calendar reminders and ability to earn CISSP credits.