During the past 4 months Microsoft Onenote file format has been (ab)used as Malware carrier by different criminal groups. While the main infection vector is still on eMail side - so nothing really relevant to write on - the used techniques, the templates and the implemented code to inoculate Malware changed a lot. So it…

Key Findings: * The use of Microsoft OneNote documents to deliver malware via email is increasing. * Multiple cybercriminal threat actors are using OneNote documents to deliver malware. * While some campaigns are targeted at specific industries, most are broadly targeted and include thousands of messages. * In order to detonate the payload, an end-user must interact with the OneNote document. * Campaigns have impacted organizations globally, including North America and Europe. * TA577 returned from a month-long hiatus in activity and began using OneNote to deliver Qbot at the end of January 2023.