Windows Defender Attack Surface Reduction Rules bypass

I discovered an easy way to bypass the Windows Defender Attack Surface Reduction Rules using code inside a macro. This issue has already been fixed with the Windows Defender virus definition version: 1.263.536.0 and above. I was first told to report this to secure@microsoft.com, but it turns out that these kinds of bypasses are considered … Continue reading Windows Defender Attack Surface Reduction Rules bypass

Putting data in Alternate data streams and how to execute it

Part 2 of this research can be found here: https://oddvar.moe/2018/04/11/putting-data-in-alternate-data-streams-and-how-to-execute-it-part-2/ I always had a fascination about ADS (Alternate data streams) and using it as part of a persistence. My first meeting with this as a persistence technique was when Matt Nelson aka @Enigma0x3 wrote a blogpost about using it: https://enigma0x3.net/2015/03/05/using-alternate-data-streams-to-persist-on-a-compromised-machine/ Quite recently I have started to play … Continue reading Putting data in Alternate data streams and how to execute it

Bypassing Device guard UMCI using CHM – CVE-2017-8625

TL;DR You could/can bypass Device Guard user mode code integrity with a custom CHM and execute code.   The last 6 months I have done some security research on my (little) spare time, because I find that very interesting. During this time, I was lucky enough to find another valid Device Guard UMCI bypass (I … Continue reading Bypassing Device guard UMCI using CHM – CVE-2017-8625

Clarification – BGInfo 4.22 – AppLocker still vulnerable

Just wanted to do a quick follow-up on this bypass. Seems that BGInfo 4.22 still can be used to bypass AppLocker using the techniques I showed in my previous post. Meaning that if you use AppLocker as whitelisting solution I guess you must deny BGInfo.exe in order to prevent this bypass. Screenshots from an AppLocker … Continue reading Clarification – BGInfo 4.22 – AppLocker still vulnerable

Bypassing Application Whitelisting with BGInfo

TL;DR BGinfo.exe older than version 4.22 can be used to bypass application whitelisting using vbscript inside a bgi file. This can run directly from a webdav server.   UPDATE: 22.05.2017 AppLocker is still vulnerable with Bginfo 4.22. A blogpost about that here: https://msitpros.com/?p=3860 UPDATE: 19.06.2017 Microsoft has thanked me in their documentation for this finding. The … Continue reading Bypassing Application Whitelisting with BGInfo