Security | Threat Detection | Cyberattacks | DevSecOps | Compliance

The Corelight Labs team prides itself on the ability to create novel Zeek and Suricata detection content that delves deep into packet streams by leveraging the full power of these tools. However this level of additional sophistication is not always required: sometimes there are straightforward approaches that only require queries over standard Zeek logs. It’s always valuable when developing detections to keep in mind that “sometimes simple does just fine.”

As organizations continue to rapidly adopt cloud services, they struggle to expand network detection and response (NDR) capabilities to their hybrid and multi-cloud environments. Network visibility is critical for security operations center (SOC) teams to secure their cloud environments and ensure they can elevate threat detection and incident investigation capabilities. However, traditional NDR solutions require management, configuration and often lack the security context needed.

“Knowing what’s on your network is the first step for any organization to reduce risk.” -CISA Director, Jen Easterly. On October 3, the Cybersecurity and Infrastructure Security Agency (CISA) issued Binding Operational Directive (BOD) 23-01: Improving Asset Visibility and Vulnerability Detection on Federal Networks.

This summer, we launched Investigator, Corelight’s SaaS-based network detection and response (NDR) solution that fuses rich network evidence with machine learning and other security analytics to unlock powerful threat hunting capabilities and accelerate analyst workflows. Today, we are pleased to share that the Investigator platform is engaged in attestation for GDPR to support customer threat hunting and incident response operations across Europe.

Security practitioners may know about common command-and-control (C2) frameworks, such as Cobalt Strike and Sliver, but fewer have likely heard of the so-called Chinese sibling framework “Manjusaka” (described by Talos in an excellent writeup). Like other C2 frameworks, we studied the Manjusaka implant/server network communications in our lab environment, and here we document some of the detection methods available. We have also open-sourced the content we describe.

In July 2022, Microsoft disclosed a vulnerability in the Windows Server Service that allows an authenticated user to remotely access a local API call on a domain controller, which triggers an NTLM request. This results in a leak of credentials that allows an attacker to authenticate to Active Directory Certification Services (ADCS) and to generate a client certificate that enables remote code execution on a domain controller.

The saying “data is king” has been around for quite a while and we all know that the world operates and makes decisions on digital data 24x7x365. But, is data king in the field of cybersecurity? I believe that evidence - not data - is what is needed to speed defenders’ knowledge and response capabilities, so let's talk about both.

Evidence is the currency cyber defenders use to pay down security debt, balancing the value equation between adversaries and the enterprise. Defenders can use evidence proactively, identifying and protecting structural risks within our zone of control. Evidence can also be used reactively by supporting detection (re)engineering, response, and recovery activities, guiding us back to identifying and protecting structural risks.

In this post, we show how enriching Zeek® logs with cloud and container context makes it much faster to tie interesting activity to the container or cloud asset involved.In cloud or container environments, layer 3 networking is abstracted away from the higher-level tasks of running workloads or presenting data. Because of this abstraction, when Zeek logs are collected for cloud or container network environments, the attribution of a network flow to actual workload or application is difficult.

This month, Microsoft announced a vulnerability in PPTP, a part of the VPN remote access services on Windows systems that runs on port 1723/tcp. Through Microsoft’s MAPP program, Corelight Labs reviewed a proof of concept exploit for this vulnerability and wrote a Zeek®-based detection for it.