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:

  1. Create a new process (victim) using a benign executable, in suspended state.
  2. Unmap the executable from that process.
  3. Allocate memory for the malicious executable at the address of the previously mapped victim executable.
  4. Write the malicious executable to the new memory area and potentially apply relocations.
  5. Adjust the entry point.
  6. 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).

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Spymax: The android RAT and it works like that….

Spymax is a mobile Remote Administration Tool (RAT) that enables an attacker to control victims’ devices through an Android malware. Once the malware is installed on a phone, the attacker can execute many attacks that highly impact the confidentiality and integrity of the victim’s data, as well as the victim’s privacy. It is powerful, widely available, and does not require root privileges on the victim’s device. In this blogpost, I show the capabilities of this RAT and analyze how its Android malware works.

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Whitepaper Endpoint Management & Monitoring Solutions Released

Over the course of the last 2 years we performed vulnerability research on several Endpoint Management & Monitoring Solutions. The results were already partially presented in security advisories which were published on this blog during the last two years. The advisories can be found here:

We also recently presented the results on Troopers 2022. Now the results have been published in a more in-depth manner in the form of a technical whitepaper. The whitepaper can be found here.

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Breaking, Misc

Security Advisories for Broadcom Automic Automation (UC4)

Updated on 20.06.22 with CVEs and link to Broadcom Security Notice.

In April 2021 we reported seven vulnerabilities in Broadcom Automic Automation (UC4) 12.3.5+hf.3. CVE IDs were assigned on 16.06.22, the corresponding Broadcom Security Notice can be found here.

The vulnerabilities have been found in the course of a research project, in which we analyzed the security of multiple Endpoint Management solutions. Similar vulnerabilities have been found in other solutions as we pointed out in previous posts about the Ivanti DSM Suite, Nagios XI, and Solarwinds N-Central.  The outcome of the research project will be published as a whitepaper and a conference talk at Troopers 2022.

In this blog post we will provide a short description of the vulnerabilities outlining the impact. More technical details will be published in the whitepaper and conference talk. All vulnerabilities were found in Broadcom Automic Automation (UC4) version 12.3.5+hf.3.

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Solving client-side controls once and for all

Missing server-side validation consistently scores a place in the OWASP Top 10. Browsers nowadays offer a lot of ways to easily implement client-side controls, increasing the usability by a lot. They automatically detect missing fields or invalid characters in your input fields and may even validate user input against a regular expressions.

However, these controls should only be considered as usability features. When sending data to a back-end system the application must always ensure data integrity by implementing encodings, validations and filters. Even for small applications this is a painful and tedious process. For each possible input, developers together with security experts have to carefully identify the context of each field, how the input is going to be used and what data requirements are present.

Furthermore, the application must always be aware of the current data encoding and apply the correct decoding before validating or filtering anything.

In this post we are going to present a new groundbreaking solution to combat missing server-side validation once and for all.

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A Tale of an OFTP2 Vulnerability

This is a guest post from Thomas Smits.

A long time ago in a galaxy far, far away….

In my ordinary life, I teach computer science at the University of Applied Sciences in Mannheim but for some months, I was an intern at ERNW learning a lot about IT security and penetration testing. One of these learnings is that old protocols can be fun and breaking them even more. But let’s start at the beginning of the story…

Back in the year 1986: Top Gun, Platoon, and Crocodile Dundee were the top-grossing films in the cinema and IBM sold the very first laptop computer, called IBM PC Convertible (model 5140). The Internet Engineering Task Force (IETF) was just founded and Boris Becker won the Wimbledon Championships for the second time. A group of engineers of the Organisation for Data Exchange by Tele Transmission in Europe (ODETTE) met and specified OFTP, a protocol to transfer files over … no, there was no Internet commercially available at that time … X.25 networks. X.25 itself dates back to 1976 and is a packet-switched protocol for WANs. The OFTP protocol tried to “address the electronic data interchange (EDI) requirements of the European automotive industry” RFC2204, page 3. With the rise of the Internet, OFTP was extended in 1997 to support TCP/IP in addition to X.25 as the transport protocol (RFC2204) and in 2007 again to include encryption and authentication (RFC5024). With RFC5024 we have the most recent specification of the protocol which is called “OFTP2”. They somehow skipped their 10-year cycle (86, 97, 07) and did not release a current specification in the last 14 years.

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Release of PTE Analysis plugins for Volatility 3

I’m happy to announce the release of several plugins for Volatility 3 that allow you to dig deeper into the memory analysis. One of those plugins is PteMalfind, which is essentially an improved version of malfind. Another one is PteResolve which, similarly to the WinDBG command !pte, allows you to inspect Page Table Entry (PTE) information for e.g., a given virtual address. In this blog post we will have a closer look at these and more plugins, and the PteEnumerator base class and what you can do with it. The memory dump used for this blog post is available here. Some of the injection tools used in this blog post can be gathered from here.

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Breaking, Misc

Change Your BLE Passkey Like You Change Your Underwear

Using a static passkey for Bluetooth Low Energy pairing is insecure. Recent versions of the Bluetooth specification contain an explicit warning about this. However, in practice, we often see static passkeys being used. Moreover, there are no public implementations of proofs-of-concept that can practically show why using a static passkey is an issue. This is why we implemented one.

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ManiMed: Ypsomed AG – mylife YpsoPump System Vulnerabilities

Manipulating Medical Devices

The Federal Office for Information Security (BSI) aims to sensitize manufacturers and the public regarding security risks of networked medical devices in Germany. In response to the often fatal security reports and press releases of networked medical devices, the BSI initiated the project Manipulation of Medical Devices (ManiMed) in 2019. In this project, a security analysis of selected products is carried out through security assessments followed by Coordinated Vulnerability Diclosure (CVD) processes. The project report was published on December 31, 2020, and can be accessed on the BSI website [1].

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Analysis of HSTS Caches of Different Browsers

The Reason

I recently stumbled upon a strange behavior in my Firefox: I visited an HTTPS-enabled website that I had visited before and saw that my Firefox connected insecurely via HTTP. I found that strange because nowadays, most websites set the HSTS header, which is supposed to force the browser to connect via HTTPS. I checked whether this website set the HSTS header – and it did. This means my Firefox was ignoring/forgetting about the HSTS header right after my visit. Continue reading “Analysis of HSTS Caches of Different Browsers”

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