Hackers have discovered a new way to bypass the macro block in Microsoft Office files and still deliver malware (opens in new tab) to unsuspecting victims through the company's suit of online collaboration apps.
Security experts at BleepingComputer found freshly distributed phishing emails equipped with OneNote attachments.
OneNote is a digital notetaking app, which people can use to create a sharable content library. It comes as part of the wider Microsoft Office suite, meaning if people have this installed, they can open OneNote files, too. While OneNote’s files, called NoteBooks, don’t support macros, they do support attachments, and that’s what the crooks are now leveraging.
Malicious VBS files
The phishing emails themselves are nothing out of the ordinary – they include fake DHL parcel notifications, fake invoices, fake shipping notifications, ACH remittance forms, and such. Instead of carrying a Word or Excel file attached, they carry a OneNote file which, if opened, seems to be blurred out, with a huge button in the middle saying “Double Click to View File”.
Double-clicking, however, runs the attachment which, in this case, is a malicious VBS file.
This file then initiates communication with the command & control (C2) server and downloads the malware.
BleepingComputer obtained a couple of these emails and determined that multiple remote access trojans and infostealers are being circulated, including the AsyncRAT and XWorm remote access trojans, as well as the Quasar Remote Access trojan.
The best way to protect against these attacks is the same as it always was – educate your employees not to download attachments and click on email links from people they don’t know, don’t trust, or whose identity cannot be confirmed. Also, they should be educated not to ignore warning messages prompted in programs such as Word, Excel, or OneNote. Other than that, having a strong antivirus solution, and a firewall, is welcome.
Finally, activating multi-factor authentication (MFA) wherever possible greatly reduces the chances of more serious compromise.
Via: BleepingComputer (opens in new tab)
English
Arabic
Belarusian
Bengali
Bosnian
Bulgarian
Chinese (Simplified)
Croatian
Czech
Danish
Dutch
Estonian
Filipino
Finnish
French
Georgian
German
Greek
Gujarati
Hausa
Hebrew
Hindi
Hmong
Hungarian
Igbo
Indonesian
Italian
Japanese
Javanese
Kazakh
Korean
Kurdish (Kurmanji)
Kyrgyz
Lao
Latvian
Lithuanian
Macedonian
Malagasy
Norwegian
Persian
Polish
Portuguese
Punjabi
Romanian
Russian
Serbian
Slovak
Slovenian
Spanish
Swedish
Thai
Turkish
Ukrainian
Vietnamese
Yoruba