{"id":81740,"date":"2018-04-04T08:00:18","date_gmt":"2018-04-04T15:00:18","guid":{"rendered":"https:\/\/cloudblogs.microsoft.com\/microsoftsecure\/?p=81740"},"modified":"2023-05-15T23:03:40","modified_gmt":"2023-05-16T06:03:40","slug":"hunting-down-dofoil-with-windows-defender-atp","status":"publish","type":"post","link":"https:\/\/www.microsoft.com\/en-us\/security\/blog\/2018\/04\/04\/hunting-down-dofoil-with-windows-defender-atp\/","title":{"rendered":"Hunting down Dofoil with Windows Defender ATP"},"content":{"rendered":"
Dofoil<\/a> is a sophisticated threat that attempted to install coin miner malware<\/a> on hundreds of thousands of computers in March, 2018. In previous blog posts we detailed how behavior monitoring and machine learning in Windows Defender AV<\/a> protected customers from a massive Dofoil outbreak<\/a> that we traced back to a software update poisoning campaign<\/a> several weeks prior. Notably, customers of Windows 10 S<\/a>, a special Windows 10 configuration that provides streamlined Microsoft-verified security, were not affected by the Dofoil outbreak.<\/p>\n In this blog post, we will expound on Dofoil\u2019s anti-debugging and anti-analysis tactics, and demonstrate how the rich detection libraries of Windows Defender Advanced Threat Protection<\/a> and Windows Defender Exploit Guard<\/a> can help during investigation.<\/p>\n We found that Dofoil was designed to be elusive to analysis. It checks its environment and stops running in virtual machine environments. It also checks for various analysis tools and kills them right away. This can make malware analysis and assessment challenging.<\/p>\n The following diagram shows the multi-stage malware execution process, which includes checks for traits of analysis environments during some stages.<\/p>\n <\/p>\n Figure 1. Dofoil multi-stage shellcode and payload execution flow<\/em><\/p>\n The table below describes the purpose of each stage. The first five stages have at least one or two different techniques that can deter dynamic or static malware analysis.<\/p>\n