Active Directory Certificate Services (ADSCS) is Microsoft’s Public Key Infrastructure (PKI) for typical Windows environments. There has been lots of blog posts on how to compromise an entire ADCS infrastructure, so I don’t want to repeat the same stuff over and over again. However, since ADCS is now a clear target with all the POCs that are available, and so
Read moreActive Directory Certificate Services (ADCS) has become more popular with all the recent attacks that has been shared publicly. The folks from SpecterOps shared a whitepaper with all the possible attacks that can lead to compromising an ADCS server. This blog post is not meant to cover all the attacks again, since there are already tons of content available on
Read moreGroup Policy is a powerful tool that attackers are using to deploy their ransomware across a network. This blog post will cover some tips on how we can hunt for this type of activity in the event logs, and so on. We will be relying on the default Windows event logs that are straight out of the box. In order
Read moreProxyShell is an attack chain that exploits three known vulnerabilities in On-Premises Exchange servers: CVE-2021-34473, CVE-2021-34523 and CVE-2021-31207. ProxyShell allows a remote unauthenticated attacker to execute arbitrary commands on an unpatched Exchange Server through port 443. The bug relies in the Client Access Service (CAS) component in Exchange and was discovered by a security researcher in 2021. The presentation of
Read moreOn-Premises Exchange servers are valuable targets for attackers, since it contains critical data and often has wide permissions within AD. Over the years, we have seen different exploits for Microsoft Exchange that could lead to a full compromise on the Exchange farm, as well as a full compromise on Active Directory. Today I would like to do a recap on
Read moreOn-Premises Exchange servers have always been a different beast when we compare it to other Microsoft products like SQL, SharePoint, and others. Exchange in general has been notorious for having wide permissions within AD. In the past, this has been described as ‘design’. Providing Exchange administrators, the flexibility to manage attributes on Exchange Server objects that are consistent with their
Read moreMicrosoft Exchange Server team has released a security update for On-Premises Exchange Servers. The October 2022, security updates are available for the following affected versions: I decided to create this blog post to summarize a bit on what this new security update would solve and what the CVEs are. I will also explain how we can check whether our Exchange
Read moreThis blog post will be targeted for organizations that are still operating with On-Premises Exchange servers. Exchange has always been an interesting piece, since it’s so tightened within AD. This can introduce security challenges as well. In this blog post, we will cover how we can implement the Exchange Split Permission Model to reduce the chance of an Exchange compromise
Read moreA Webshell is a malicious script that an attacker can drop on a webserver to launch additional attacks and establish persistence. Before a Webshell is dropped, it is usually the case that an attacker has successfully obtained SYSTEM level access on the targeted server in order to upload the Webshell. A Webshell may provide a set of functions to execute
Read moreThis will be a high-level summary of the different logs that can be found on an On-Premises Exchange server, which can be useful during an IR. For each log, I’ll try to explain what we can achieve with it. Not all logs are useful, so I’ve only picked the one’s that I’m aware of and believe are useful. IIS logs
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