Publications

PrideLocker - a new fork of Babuk ESX encryptor

Mon, 12/05/2022 - 13:33
CSIRT
A few months after the leak of Babuk source code in September 2021, new ransomware families with very similar capabilities already seem to emerge. During an incident response, Synacktiv's CSIRT detected a new ESX encryptor dubbed PrideLocker that is based on Babuk ESX encryptor, with new additions. This article provides an in-depth analysis of PrideLocker, and a method using IDAPython to decrypt its strings, as well as tips to detect its encryption capabilities.

Legitimate RATs: a comprehensive forensic analysis of the usual suspects

Thu, 10/20/2022 - 13:37
CSIRT
Legitimate remote access tools are more and more part of threat actors toolbox: in order to gain remote access on targets, keep persistence, deploy malicious payload as well as leveraging trusted connections between an IT provider and its customers. Therefore, detection and incident response teams must have a good grasp on traces left by those tools on the system. In this context, this article aims to collect host forensic evidence of four famous legitimate remote access tools.

Traces of Windows remote command execution

Tue, 09/13/2022 - 15:34
CSIRT
Pentest
A real ninja leaves no traces. However, in the Windows context, a lot of information are disseminated when performing actions and can be leveraged by DFIR analysts. Focusing on remote command execution techniques used by attackers and red-teamers, this article aims to get a collection of artifacts that can collected by analysts.

CCleaner forensics

Mon, 06/20/2022 - 15:58
CSIRT
During a ransomware attack, right after the ransomware was launched, we noticed the use of CCleaner as an anti-forensic tool to cover the attacker’s action. The following article aims to explore some key features of this tool from a forensic perspective. We will see how to identify the items that have been deleted and how they could be recovered. We focused on the free desktop version v6.00.9727.

Unransomware

Mon, 01/31/2022 - 10:45
CSIRT
During a ransomware incident, CSIRT Synacktiv noticed that the bitlocker mechanism was used to encrypt company and user files. This blogpost does not intend to retrace the whole incident response process. The idea is to illustrate how we managed (or not) to recover encryption keys and save a few workstations from their terrible fate. The incident took place few months ago.

Yet another BEC investigation on M365

Mon, 11/22/2021 - 15:15
CSIRT
Several materials already describe this type of attack, this document is an operational feedback from the CSIRT Synacktiv on several BEC incidents based on Microsoft 365 service. This is the part one of this publication.