Targeted attacks are moving away from traditional malware to stealthier techniques that involve abusing standard system tools and protocols that are less frequently monitored.
Targeted attacks are moving away from traditional malware to stealthier techniques that involve abusing standard system tools and protocols, some of which are not always monitored.
The latest example is an attack dubbed DNSMessenger, which was analyzed by researchers from Cisco Systems’ Talos team. The attack starts with a malicious Microsoft Word document distributed through an email phishing campaign.
When opened, the file masquerades as a « protected document » secured by McAfee, an antivirus brand now owned by Intel Security. The user is asked to click on the ‘enable content’ button in order to view the document’s content, but doing so will actually execute malicious scripting embedded within.
The script is written in PowerShell, a powerful scripting language built into Windows that allows for the automation of system administration tasks. What’s interesting is that until this point, everything is done in memory, without writing any malicious files to disk.
The second stage is also done in PowerShell and involves checking for several parameters of the environment, like the privileges of the logged-in user and the version of PowerShell installed on the system.
