While Microsoft documents that leverage malicious, embedded Visual Basic for Applications (VBA) macros are not a new thing, their use has noticeably increased this year, thanks in part to their simplicity and effectiveness.
Some threat actors commonly use this class of malware to drop a second stage payload on victim systems. Even though Microsoft attempts to mitigate this threat by disabling macros by default, the percentage of users who explicitly bypass this protection and enable macros remains high.
Exploiting the human factor, the most effective attacker strategy is the tried and true spear phishing attack, ideally made to look authentic by appearing to originate from a legitimate organization/individual and containing role-relevant or topic-of-interest content to entice its intended target. This post examines an information stealer campaign that leveraged a VBA macro script, focusing on its progression, from delivery to Command and Control (C2), and its attribution to a malicious actor for context on objectives and motivation.
Delivery and Exploitation
The recent campaign started with an email sent to an employee responsible for processing financial statements at a global financial organization (Figure 1). The sender’s email address was spoofed as originating from an energy company. Subsequent analysis would show that this façade was very thin; yet, it is often all that is required to encourage a user to open an attachment or click on a link that then executes malicious code. Continue reading "Examining a VBA-Initiated Infostealer Campaign"
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