A new wave of phishing messages distributing the QakBot malware has been observed, more than three months after a law enforcement effort saw its infrastructure dismantled by infiltrating its command-and-control (C2) network.
Microsoft, which made the discovery, described it as a low-volume campaign that began on December 11, 2023, and targeted the hospitality industry.
"Targets received a PDF from a user masquerading as an IRS employee," the tech giant
said in a series of posts shared on X (formerly Twitter).
"The PDF contained a URL that downloads a digitally signed Windows Installer (.msi). Executing the MSI led to Qakbot being invoked using export 'hvsi' execution of an embedded DLL."