Posts

Threat Hunting - Zero to Hero

Image
In my Securing Windows environments post, I touched upon logging and SIEM but I didn't go deeper as the post became too lengthy already. As a reference, I stated the following:

"... All of the things described up to this point, aim to reduce the attack surface (reducing the risk of successful compromise) and the impact should one occur ... Now, if you think about this, the Penetration testers will be running tools and scripts, which are not normally executed in your environment so that puts you a step further, because it will all be executed on a device that you own. At this point, having and analyzing logs (default Windows logs only are insufficient to trace activity) is fundamental. In fact, in 2019, there should be no excuse for not having a SIEM system, even if it is a free of charge one - ELK stack or Graylog (although it may not have every feature you wish it did)."

Basics The above refers to utilizing the available logs to perform Threat Hunting. Threat hunting is …

The mind-blowing Kerberos "Use Any Authentication Protocol" Delegation

Image
Kerberos delegation has been in the spot light for some time now and the risks behind it have been outlined in quite a few blogs and conference presentations - I particularly recommend reading https://adsecurity.org/?p=1667 and https://www.harmj0y.net/blog/redteaming/another-word-on-delegation/. For some time, it was my incorrect understanding that unconstrained delegation is a massive problem while constrained/resource based is less destructive. That is however not the case, and the exploitation that is to follow absolutely blew my mind the first time I saw it in "action".

When a service account is set for "Use any authentication protocol" delegation, it means that the service account is allowed to delegate without being required to prove that a user authenticated to it! In normal words, just saying "I shall pass because I am the administrator, trust me!" opens the door with no questions asked and no one verifying that you are in fact the administrator. …

Securing Windows environments

Image
Intro Securing windows environments in a way that prevents lateral movement and/or escalation of privileges has become an incredibly difficult task. The research and tools created in the past 2-3 years have been simply amazing, which helped to identify new attacks and vulnerabilities, while lowering the sophistication required to exploit them. The easiest way to ensure that your environment is built in a secure manner, is to rebuild it from scratch with a security architect behind the design. As Microsoft states, one may never trust Active Directory, if it has been compromised, unless it is possible to return to a known good state. Unfortunately, creating a new environment is unrealistic, so in this post, I'll focus on identifying common and deadly "flaws" in the current implementation and provide techniques and procedures that I recommend, to increase your Cyber maturity and capabilities to withstand an intrusion or limit the impact of one, should it occur. The informa…