So in order to run them, either the data about the file’s zone – sometimes called the Mark of the Web – needs to be removed, or the file has to come from a zone with a higher level of trust than that of the internet. After this change is deployed, macros are still blocked from running as before. With a phased rollout starting in April 2022, Microsoft has been tightening up the default handling of macro-enabled files downloaded from the internet by entirely removing the option to click “Enable Content”. So long as an admin policy is not in place to prevent recipients from clicking through, the macros successfully load and run.Īlthough the blocking of macros helped limit the delivery of malware, malicious actors, such as the Emotet operators, adapted their efforts by focusing on duping victims into clicking through to enable macros. Since then, two clicks have been typically required to enable macros: first, clicking on “Enable Editing”, which removes the document from Protected View, a security feature in place since Office 2010 that provides a read-only, sandboxed environment second, clicking on “Enable Content”, which allows the macros to run. Recognizing this potential abuse of macros, during the heyday of Word 97 Microsoft introduced the first built-in security feature in Word that blocked Visual Basic for Applications (VBA) macros from running:įigure 9. Mitigating macro malwareĮmailing documents that contain macros is both a common occurrence in corporate environments and can serve as a technique to deliver malware when those macros are malicious. By using a Beacon, the Emotet operators can decrease the time to deploy their final payload – often ransomware. When Emotet’s operators first resurrected their botnet from the takedown efforts in late 2021, another campaign was discovered that uses Cobalt Strike Beacon, a popular pentesting tool. ![]() If extracted and executed, these files dropped and ran Emotet. In an earlier test campaign between April 4 th and April 19 th, the Emotet operators attracted victims to a ZIP archive, stored on OneDrive, containing Microsoft Excel Add-in (XLL) files, which are used to add custom functions to Excel. Most detections were in Japan (28%), Italy (16%), and Mexico (11%). Emotet’s operators use shortcut (LNK) files to deliver malware Taking note of the change, Emotet’s developers have shifted to experimenting with different techniques to replace their dependence on macros as the initial code stage of their malware delivery platform.īetween April 26 th and May 2 nd, 2022, ESET researchers picked up a test campaign run by Emotet operators where they replaced the typical Microsoft Word document with a shortcut (LNK) file as the malicious attachment.įigure 7. Microsoft’s move (on February 30 th 2022, so to speak) to throw out the “Enable Content” button came at a time for Emotet when, after recovering from last year’s takedown efforts, it had been churning out spam campaigns en masse in March and April 2022. Should the victim extract the macro-laden Word document from the ZIP archive, open it, and then click “Enable Content”, the malicious macros can run, ultimately downloading Emotet. Emotet’s operators use macro-enabled Word documents to deliver malware This is, of course, a very effective way of adding legitimacy to a malicious email:įigure 2. It started stealing email conversations found in compromised systems’ inboxes and reusing them in its spam campaigns. In 2018, Emotet resuscitated an effective technique – email thread hijacking – to increase the likelihood of a potential victim opening the email attachments. steal all email messages and attachments from compromised systems.steal email addresses and names from the compromised system’s Microsoft Outlook instance.abuse legitimate Nirsoft applications, such as MailPassView and WebBrowserView, that can recover passwords from popular email clients and web browsers, respectively.turn compromised systems into proxies within its command-and-control infrastructure. ![]() brute-force network share usernames and passwords.spread to nearby, insecure Wi-Fi networks by compromising connected users.spread further by assembling and delivering spam emails. ![]() Thus, once Emotet is running on a computer, it typically downloads and executes other strains of malware, such as Dridex, Gootkit, IcedId, Nymaim, Qbot, TrickBot, Ursnif, and Zbot.Įmotet has a modular program design, with a main module that is disseminated through vast spam campaigns that distribute emails containing malicious Microsoft Word documents. First sighted as a banking trojan in June 2014, Emotet has since changed drastically into a crime-as-a-service platform, selling access to compromised systems to other criminal groups.
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