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C2

Detecting Exposed Cobalt Strike DNS Redirectors

A technique was developed to detect exposed Cobalt Strike DNS redirectors by identifying DNS servers that consistently return the same IP address for all domain queries. The method involves scanning DNS servers and analyzing their response patterns to identify potential Cobalt Strike infrastructure. An internet-wide survey was conducted to validate the detection approach, revealing multiple potential Cobalt Strike DNS servers.

Using and detecting C2 printer pivoting

A novel Command & Control (C2) technique using printer infrastructure for covert communication is explored in this article. The method involves placing print jobs in a paused state and using document names for data transfer. Multiple detection opportunities are detailed across endpoints, networks, and print servers to identify this stealthy communication method.

Introducing LDAP C2 for C3

A new Command & Control (C2) channel for C3 has been introduced using LDAP for covert communication within networks. The technique enables lateral movement by leveraging user attributes with minimal account compromise. A quick start guide is provided to help deploy LDAP-based C2 channels in network environments.

Attack Detection Fundamentals: C2 and Exfiltration - Lab #1

This article demonstrates detection techniques for PowerShell Empire's Command and Control (C2) traffic. Network indicators like default URIs, user agents, and server responses are analyzed to identify potential malicious communication patterns. A Snort rule is developed to detect these specific network traffic characteristics associated with PowerShell Empire.

Attack Detection Fundamentals: C2 and Exfiltration - Lab #2

This article demonstrates techniques for detecting DNS Command and Control (C2) channels using the dnscat2 tool. Detection strategies include analyzing DNS traffic for unique strings like "dnscat", unusual request sizes, and uncommon DNS record types. Practical Snort rule examples are provided to identify potential DNS-based exfiltration and C2 communication.

Attack Detection Fundamentals: C2 and Exfiltration - Lab #3

This article explores using Dropbox as a command and control (C2) channel for malware communication. Detection strategies are discussed using Windows ETW and Sysmon telemetry, focusing on identifying suspicious network behaviors like anomalous DNS queries and API endpoint interactions. Key detection opportunities include monitoring beaconing patterns and unusual web requests to Dropbox API endpoints.

Attack Detection Fundamentals: Discovery and Lateral Movement - Lab #3

This article explores lateral movement techniques using C3 and Covenant to pivot through file shares in a Windows environment. The lab demonstrates detection strategies by analyzing file share access logs and Event Tracing for Windows (ETW) events to identify suspicious .NET module loading and communication patterns. Key detection techniques include monitoring file share object access logs and tracking anomalous CLR module loading in processes.

Attack Detection Fundamentals: Discovery and Lateral Movement - Lab #4

This article explores lateral movement techniques using PsExec in Windows environments. It details detection strategies for identifying suspicious remote execution activities through Windows event logs and Sysmon telemetry. Key detection opportunities include monitoring service creation events, process creation logs, and named pipe interactions during remote command execution.

Attack Detection Fundamentals: Discovery and Lateral Movement - Lab #5

This article explores lateral movement techniques using Windows Management Instrumentation (WMI) in cybersecurity attack detection. The lab demonstrates detection strategies for both native WMIC commands and Impacket's wmiexec tool. Key detection opportunities include analyzing process creation events, network traffic patterns, and examining parent-child process relationships during WMI-based lateral movement attacks.

  • 10 Mar 2020

Making Donuts Explode – Updates to the C3 Framework

The C3 framework's "Exploding Donut" release introduces significant updates to cybersecurity operations. Key improvements include integration with the Covenant C2 framework and Donut for compressed shellcode generation. The ChannelLinter project was added to simplify channel development for cybersecurity professionals.

"Tasking" Office 365 for Cobalt Strike C2

A novel Command and Control (C2) technique for Cobalt Strike was demonstrated using Office 365's Exchange Web Services. The technique leverages Outlook tasks as a communication channel to transmit malicious traffic through a legitimate service. The proof-of-concept shows how attackers can use the External C2 interface to create covert communication paths through enterprise collaboration tools.

Safer Shellcode Implants

This article discusses techniques for creating safer shellcode implants by implementing runtime security controls. The proposed methods include ensuring single execution through mutex checks, validating the target endpoint using host-specific identifiers, and adding an expiry time to control the implant's lifecycle. Implementation examples are provided in both assembly and C languages to demonstrate these security controls.

Egress Checking

The EgressCheck Framework is a tool designed to help penetration testers and system administrators identify network egress opportunities. It generates traffic across multiple ports and protocols, capturing connection attempts using tcpdump. The framework supports both TCP and UDP scanning, and can generate one-liner scripts for Python and PowerShell.