incident analysis – Insinuator.net

Misc

September 6, 2023 by Frank Block

Identification of (malicious) modifications in memory-mapped image files

I’m happy to announce the publication of the paper Windows memory forensics: Identification of (malicious) modifications in memory-mapped image files at this years DFRWS USA, and the release of the corresponding volatility plugin. With this research came also an update to the Ptenum family (affecting especially the ptemalfind plugin), which makes the plugins reliable in identifying modified pages despite memory combining, so make sure to grab the newest version from the Github repository.

This blog post will mainly cover the imgmalfind plugin and some use cases. For detailed information on the theory behind the plugins, see the paper.

Continue reading “Identification of (malicious) modifications in memory-mapped image files”

Breaking

September 29, 2022 by Frank Block

Some experiments with Process Hollowing

Process Hollowing is a technique used by various malware families (such as FormBook, TrickBot and Agent Tesla) to hide their malicious code within a benign appearing process. The typical workflow for setting up such a hollowed process is as follows:

Create a new process (victim) using a benign executable, in suspended state.
Unmap the executable from that process.
Allocate memory for the malicious executable at the address of the previously mapped victim executable.
Write the malicious executable to the new memory area and potentially apply relocations.
Adjust the entry point.
Resume process.

We will refer to this as the “normal” Process Hollowing workflow. There are also variants of this technique, one being to not unmap the original executable and to allocate the new memory somewhere else. We will call this one no-unmap. But wait, why does malware not simply overwrite the existing executable but creates a new memory area which stands out due to its characteristics? In this blog post we will have a closer look at this overwrite approach but also on the no-unmap method, their effects on analysis/detection tools and on some tricks to make the detection harder. We are also releasing Proof of Concept implementations of all mentioned tools/plugins (the links are at the end of this post).

Continue reading “Some experiments with Process Hollowing”

Misc

April 23, 2021 by Florian Bausch

Of Corona, Buggy Audio Drivers and Industrial Espionage

The Situation

Last year, the CISO of a customer sent me a laptop for analysis. The reason was that he feared the company could have been victim of industrial espionage. Starting in spring 2020, the IT help desk got several employee laptops with full hard drives, caused by a huge amount of audio recordings. The audio files contained recordings even of highly sensitive telephone conferences. An automated scan on all employee computers for such audio recordings showed that about 300 devices were affected. Continue reading “Of Corona, Buggy Audio Drivers and Industrial Espionage”

Misc

October 30, 2019 by Frank Block

Dissection of an Incident – Part 2

After our last blogpost regarding Emotet and several other Emotet and Ransomware samples that we encountered, we recently stumbled across a variant belonging to the Gozi, ISFB, Dreambot respectively Ursnif family. In this blogpost, we want to share our insights from the analysis of this malware, whose malware family is mainly known for being a banking trojan that typically tries to infect browser sessions and sniff/redirect data. In particular, we are going to provide details about the first stage Word Document, the embedded JavaScript/XSL document, an in-depth runtime analysis of the downloaded executable, and some details regarding detection.

Also, with this blog post, we are releasing a Rekall plugin called pointerdetector that enumerates all exported functions from all DLLs and searches the memory for any pointer to them (essentially a search for dynamically resolved APIs). This plugin can assist in identifying dynamically resolved APIs and especially memory regions containing DLLs loaded with techniques such as reflective DLL injection. This blog post will contain some examples illustrating the usage of this plugin, as well.

If you are interested in a hands-on analysis of Incidents and malicious files, we are giving another round of our Incident Analysis workshop at Troopers20.

Continue reading “Dissection of an Incident – Part 2”

Misc

July 18, 2019 by Prof. Dr.-Ing. Andreas Dewald

Emotet at Heise, Emotet there, Emotet everywhere – Dissection of an Incident

After the Emotet Incident at Heise, where ERNW has been consulted for Incident Response, we decided to start a blogpost series, in which we want to regularly report on current attacks that we observe. In particular we want to provide details about the utilized pieces of malware, different stages, and techniques used for the initial infection and lateral movement. We hope that this information might help you to detect ongoing incidents, apply countermeasures, and in the best case to figure out proactive countermeasures and security controls beforehand.

Continue reading “Emotet at Heise, Emotet there, Emotet everywhere – Dissection of an Incident”

Misc

October 18, 2018 by Prof. Dr.-Ing. Andreas Dewald

Comparison of our tool afro (APFS file recovery) with Blackbag Blacklight and Sleuthkit

At this years ARES conference, Jonas Plum (Siemens) and me (Andreas Dewald, ERNW Research GmbH) published a paper about the forensic analysis of APFS, file system internals and presented different methodologies for file recovery. We also publicly released a tool implementing our presented approaches, called afro (APFS file recovery).

Continue reading “Comparison of our tool afro (APFS file recovery) with Blackbag Blacklight and Sleuthkit”