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Lateral movement cobalt strike9/10/2023 ![]() If there is no task available, the server will return default response. $SleepTime = Get-Random -Minimum $SleepMin -Maximum $SleepMaxĪfter sleep agent executes GetTask method to make a request to Command & Control Server and retrieve a task for further execution. $SleepMax = ((1+$script:AgentJitter)*$script:AgentDelay) $SleepMin = ((1-$script:AgentJitter)*$script:AgentDelay) Secureworks meanwhile found Cobalt Strike playing a role in 19 of the network intrusions it investigated in 2021. This was achieved by connecting via SMB and starting a service that would execute an encrypted PowerShell command with embedded Cobalt Strike SMB beacons. no interactive/delay 0) then sleep for the specified time Cobalt Strike was the single most widely seen offensive tool used by Advanced Persistent Threat (APT) actors in the last quarters of 2021, according to analysis by security firm Trellix. The threat actors attempted and successfully managed to pivot laterally to various hosts on the domain. In both tools Empire Powershell and CobaltStrike there is a parameter called jitter which makes those sleeps more random. Sleep is needed to make less requests and stay under radar unless there is a specific need to make more connections to Command & Control for example in case of faster data exfiltration over Command & Control channel. Great way to explain how it works is using agent code snippets from Empire Powershell – another Post-Exploitation framework widely used by malicious actors which deserves a separate article regarding its detection.Īt first, agents sleep for specific time configured with a sleep parameter in Empire Powershell or sleep command in Cobalt Strike. What is beaconing?īeaconing is the term used to describe communication between agent and Command & Control Server. With that said CobaltStrike network activity still can be detected due to the fact that some behavior characteristics are harder to customize than others, for example the way beacon check-ins for available tasks on Command & Control Server. And its Malleable C2 Profiles settings will try to blend Command & Control communication into millions of network flows which go in and out in your organization. Besides widely used HTTP, HTTPs, DNS protocols for Command & Control communication, CobaltStrike supports SMB which often becomes unnoticed by SOC analysts.īecause CobaltStrike is highly customizable, it makes Endpoint protection solutions trivial to bypass. Out of the box CobaltStrike has port scanning, different lateral movement techniques, file browser, keylogger and even remote desktop control via VNC. Below is a statistics made by RecordedFuture for previous year. This growth is explained by the fact that CobaltStrike was leaked multiple times and became more accessible for malicious groups. The research paper on Lateral Movement from JPCERT, linked in the references below, is a definitive resource on this topic and covers many other techniques aside from PsExec.CobaltStrike became part of the Cybercrime’s “toolset” almost in every Company breach. DCOM abuse and lateral movement with Cobalt Strike T06:53:02 Description. He details scripting an Aggressor Script for Matt Nelson’s MMC20.Application Lateral Movement technique. Many will be familiar with its use amongst system administrators, and many threat actors have used it as a means of lateral movement! In terms of detection opportunities, we’re going to be focusing largely on the event log entries that it produces, augmenting this with telemetry from Sysmon. Introduction When researching lateral movement techniques I came across a post from Raphael Mudge (of Cobalt Strike fame). In several cases, we’ve also taken a look at the code bases of our attacker tooling to identify opportunities to detect it.įor this lab, we’re going to be taking a look at the SysInternals tool, PsExec. However, there are only a handful of publicly known techniques that are typically used. We also used object access audit logs for the purposes of detecting share access and our use of an exposed share for pivoting using C3. 1 It’s no secret that attackers are looking for new techniques to execute lateral movement. In the previous labs ( here, here and here), we’ve looked at Discovery techniques for enumerating users and groups, and opportunities to detect this based on suspicious LDAP queries using telemetry from ETW. As with previous workshops, the following blog provides a fourth step-by-step guide to recreating the demos from that Discovery and Lateral Movement workshop, as well as exercises to further the reader's understanding of the concepts shown.Ī recording of the workshop can be found here. ![]() We also explored the detection strategies that can be employed to spot these using our own detection stacks. ![]()
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