Alexander Schmitz

Mr. Alexander Schmitz

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 January 2025 in Electronics
Verified
Journal Article
Open access
PDF file
LBLukas Beierlieb
Lukas Beierlieb
ASAlexander Schmitz
Alexander Schmitz
RSRaphael Springer
Raphael Springer
CDChristian Dietrich
Christian Dietrich
LILukas Iffländer
Lukas Iffländer
Virtual Machine Introspection (VMI) is a powerful technology used to detect and analyze malicious software inside Virtual Machines (VMs) from outside. Asynchronously accessing the VM’s memory can be insufficient for efficiently monitoring what is happening inside of a VM. Active VMI introduces breakpoints to intercept VM execution at relevant points. Especially for frequently visited breakpoints, and even more so for production systems, it is crucial to keep their performance overhead as low as possible. In this paper, we provide a systematization of existing VMI breakpoint implementation variants, propose workloads to quantify the different performance penalties of breakpoints, and implement them in the benchmarking application bpbench. We used this benchmark to measure that, on an Intel Core i5 7300U, SmartVMI’s breakpoints take around 81 µs to handle, and keeping the breakpoint invisible costs an additional 21 µs per read access. The availability of bpbench facilitates the comparison of disparate breakpoint mechanisms and their performance optimization with immediate feedback.

3 January 2025 in Preprints.org
Verified
Preprint
Open access
PDF file
LBLukas Beierlieb
Lukas Beierlieb
ASAlexander Schmitz
Alexander Schmitz
CDChristian Dietrich
Christian Dietrich
RSRaphael Springer
Raphael Springer
LILukas Iffländer
Lukas Iffländer
Virtual Machine Introspection (VMI) is a powerful technology used to detect and analyze malicious software inside Virtual Machines (VMs) from outside. Asynchronously accessing the VM’s memory can be insufficient for efficiently monitoring what is happening inside of a VM. Active VMI introduces breakpoints to intercept VM execution at relevant points. Especially for frequently visited breakpoints, it is crucial to keep their performance overhead as small as possible. In this paper, we provide an systematization of existing VMI breakpoint implementation variants, propose workloads to quantify the different performance penalties of breakpoints, and implement them in the benchmarking application bpbench. We used this benchmark to measure that, on an Intel Core i5 7300U, SmartVMI’s breakpoints take around 81 µs to handle, and keeping the breakpoint invisible costs an additional 21 µs per read access. The availability of bpbench allows the comparison of different breakpoint mechanisms, as well as their performance optimization with immediate feedback.

16 October 2025 in Eng
Verified
Journal Article
Open access
PDF file
LBLukas Beierlieb
Lukas Beierlieb
ASAlexander Schmitz
Alexander Schmitz
AKAnas Karazon
Anas Karazon
ALArtur Leinweber
Artur Leinweber
CDChristian Dietrich
Christian Dietrich
Virtual Machine Introspection (VMI) is a powerful technology used to detect and analyze malicious software inside Virtual Machines (VMs) from the outside. Asynchronous access to the VM’s memory can be insufficient for efficient monitoring of what is happening inside of a VM. Active VMI introduces breakpoints to intercept VM execution at relevant points. Especially for frequently visited breakpoints, and even more so for production systems, it is crucial to keep performance overhead as low as possible. In this paper, we present an empirical study that compares the performance of four VMI breakpoint-implementation variants—EPT switching (SLAT view switching) with and without fast single-stepping acceleration, instruction repair, and instruction emulation—from two VMI applications (DRAKVUF, SmartVMI) with the XEN hypervisor on 20 Intel Core i processors ranging from the fourth to the thirteenth generation. Instruction emulation was the fastest method across all 20 tested platforms. Modern processors such as the Intel Core i7 12700H and Intel Core i9 13900HX achieved median breakpoint-processing times as low as 15 µs for the emulation mechanism. The slowest method was instruction repair, followed by EPT switching and EPT switching with FSS. The order was the same for all measurements, indicating that this is a strong and generalizable result.

15 September 2025 in Preprints.org
Verified
Preprint
Open access
PDF file
LBLukas Beierlieb
Lukas Beierlieb
ASAlexander Schmitz
Alexander Schmitz
AKAnas Karazon
Anas Karazon
ALArtur Leinweber
Artur Leinweber
CDChristian Dietrich
Christian Dietrich
Virtual Machine Introspection (VMI) is a powerful technology used to detect and analyze malicious software inside Virtual Machines (VMs) from outside. Asynchronously accessing the VM’s memory can be insufficient for efficiently monitoring what is happening inside of a VM. Active VMI introduces breakpoints to intercept VM execution at relevant points. Especially for frequently visited breakpoints, and even more so for production systems, it is crucial to keep their performance overhead as low as possible. In this paper, we present an empirical study that compares the performance of four VMI breakpoint implementation variants–EPT switching (SLAT view switching) with and without fast single-stepping acceleration, instruction repair and instruction emulation–from two VMI applications (DRAKVUF, SmartVMI), with the XEN hypervisor, on 20 Intel Core i processors ranging from the 4th to the 13th generation. Regarding the time required to process a breakpoint hit, we found that on all platforms: instruction repair > EPT switching EPT switching fast single-step > instruction emulation. More modern processors such as the Intel Core i7 12700H and Intel Core i9 13900HX achieved median breakpoint processing times as low as 15μs.

30 April 2025 in arXiv
Verified
Preprint
Open access
PDF file
RSRaphael Springer
Raphael Springer
ASAlexander Schmitz
Alexander Schmitz
ALArtur Leinweber
Artur Leinweber
TUTobias Urban
Tobias Urban
CDChristian Dietrich
Christian Dietrich
Function detection is a well-known problem in binary analysis. While previous research has primarily focused on Linux/ELF, Windows/PE binaries have been overlooked or only partially considered. This paper introduces FuncPEval, a new dataset for Windows x86 and x64 PE files, featuring Chromium and the Conti ransomware, along with ground truth data for 1,092,820 function starts. Utilizing FuncPEval, we evaluate five heuristics-based (Ghidra, IDA, Nucleus, rev.ng, SMDA) and three machine-learning-based (DeepDi, RNN, XDA) function start detection tools. Among the tested tools, IDA achieves the highest F1-score (98.44%) for Chromium x64, while DeepDi closely follows (97%) but stands out as the fastest by a significant margin. Working towards explainability, we examine the impact of padding between functions on the detection results. Our analysis shows that all tested tools, except rev.ng, are susceptible to randomized padding. The randomized padding significantly diminishes the effectiveness for the RNN, XDA, and Nucleus. Among the learning-based tools, DeepDi exhibits the least sensitivity and demonstrates overall the fastest performance, while Nucleus is the most adversely affected among non-learning-based tools. In addition, we improve the recurrent neural network (RNN) proposed by Shin et al. and enhance the XDA tool, increasing the F1-score by approximately 10%.

4 June 2024
Verified
Conference Paper
Open access
RSRaphael Springer
Raphael Springer
ASAlexander Schmitz
Alexander Schmitz
ALArtur Leinweber
Artur Leinweber
TUTobias Urban
Tobias Urban
CDChristian Dietrich
Christian Dietrich