Intruders taught Trojan Qbot to hide in branches of existing messaging

Qbot banker disseminator that is known since 2009 launched another email-campaign, though with some innovations.

Hyperlink on download for Trojan virus for Windows inserted in real answer on mail that was already sent by potential victim. According to JASK notification, email becomes inbuilt in existing branch of email correspondence. This allows lulling target’s vigilance and bypassing spam protection.

“This email was not blocked by an anti-spam gateway. It was a context-aware targeted response to an existing email thread,” wrote Greg Longo, senior threat analyst with JASK, in an email-based interview.

He also added that aim of such attacks is stealing confidential financial information, including back account credentials.

Infecting happens by the following algorithm. Fishing letter arrives with the link on Microsoft OneDrive file that delivers Microsoft Visual Basic Scripting Edition (VBScript) in compressed ZIP-archive. If this archive is open, attack starts the legitimate BITSAdmin Windows utility. This, in its turn, leads to activation of Wscript.exe that is another Windows utility that used for uploading Qbot «august.png» malware program from hackers’ server.

This trick applied now for delivery of long-living Trojan Qbot, also known as QakBot and Pinkslipbot. Trojan that specializes on stealing data for access to bank accounts helps cybercriminals for more than 10 years. In its popularity contributes ability to reproduce itself through removable shared media devices, and polymorphism – constant change of program code that allows bypassing antivirus protection.

Source: https://threatpost.com