Compass Security Blog

Offensive Defense

COM Cross-Session Activation

Once again, reading blogs and tweets from James Forshaw led me to wonder how things work. This time, I was working on DCOM for my last blog post and while reading about cross-session activation, I had trouble believing what I was reading.

Continue reading

Three-Headed Potato Dog

Earlier this year, several security researchers published research about using DCOM to coerce Windows systems to authenticate to other systems. This can be misused to relay the authentication to NTLM or Kerberos, to AD CS over HTTP for instance. This sounds like a hot and complex topic. Let’s take a look back how this started […]

Continue reading

Microsoft Teams Covert Channels Research

With the rise of remote working, Microsoft Teams has become the de-facto standard for video conferences, chat, and collaboration. The nature of the Teams architecture are some central systems that route information between parties. With that comes that Teams client software must be allowed to communicate to the Internet. Microsoft even recommends letting Teams traffic bypass inspection proxies for compatibility reasons. Its network communication pattern has significant overlap with malicious C2 traffic und thus it is nearly impossible for blue teams to spot adversary communication. Therefore, Teams is an interesting candidate to be abuses for C2 traffic. Thus, we put some research into this.

Continue reading

Relaying NTLM to MSSQL

Readers of this blog probably know that I like to try NTLM relaying over all protocols possible! Relaying to Microsoft SQL (MSSQL) is known to work when using the default weak configuration.

With this blog post, we show some dangerous configurations and release a small tool to automate NTLM relaying in these cases.

Continue reading

Lenovo Update Your Privileges

A journey into the discovery of privilege escalation vulnerabilities in the Lenovo Update process.

Continue reading

Securing Connections to your Remote Desktop

When accessing a remote server, one should always assume it has been compromised or might be in the near future. It is particularly crucial for users with administrative privileges to establish a secure connection to the Remote Desktop Protocol (RDP) service in order to not fall victim to credential theft or impersonation. To achieve this, there exist several measures in Windows. In this blog post, we’ll look at some of them, their benefits and their drawbacks.

Continue reading

Compiling a Mimikatz Module for Dumping Citrix Credz

Sometimes, the good old credential dumping techniques just won’t work. This is the story of how a bad actor could dump credentials on a fully-patched, monitored and hardened workstation.

Continue reading

Relaying to AD Certificate Services over RPC

In June last year, the good folks at SpecterOps dropped awesome research on Active Directory Certificate Services (AD CS) misconfigurations. Since then, we find and report these critical vulnerabilities at our customers regularly. One of these new attack path is relaying NTLM authentication to unprotected HTTP endpoints. This allows an attacker to get a valid […]

Continue reading

No Passwords More Problems

Passwordless products promise greater security and convenience by allowing users to log in to Windows systems with only their smartphone. But what is going on behind the scenes and how could a domain’s security stance be worsened by such a solution? In this post I will explain how these products are implemented and detail the vulnerabilities and weaknesses discovered in three tested products.

Continue reading

BloodHound Inner Workings & Limitations – Part 3: Session Enumeration Through Remote Registry & Summary

BloodHound is the way to go to for finding attack paths in an Active Directory (AD) environment. However, it is not always clear how the data is gathered without looking at the code of SharpHound, the data ingestor for BloodHound. Microsoft hardened their systems over time through updates, which makes enumeration of Active Directory (AD) […]

Continue reading

« Older posts