Understanding Malware Development Languages

Introduction

A select number of languages are preferences over hundreds to write code in. This article discusses the pros and cons behind each, as well as some of the reasons why the language has been chosen. They are listed in order of popularity:

Though languages like "Go" have taken off, numerous studies and observations indicate that the majority of sophisticated malicious programs with extensive functionality are primarily developed in C and C++. These languages are favored for creating serious threats because they provide low-level access to system resources, allow direct memory manipulation, and enable the construction of complex structures that hinder analysis and detection.

Another factor contributing to their popularity in the cybercriminal ecosystem is their portability - C and C++ have minimal runtime dependencies, making it easier to compile and adapt malicious code across different platforms. Cybersecurity experts also point out that C, in particular, is prone to undefined behavior, which often results in security flaws and exploitable vulnerabilities in software infrastructure.

Python is extensively used in malware development where speed, flexibility, and automation are prioritized over stealth. Its simple syntax and vast ecosystem of libraries enable rapid creation of functional malware, making it particularly attractive to cybercriminal groups and less mature threat actors. Python-based malware is commonly observed in data exfiltration tools, cryptominers, ransomware components, and botnet management scripts.

Although Python malware often requires an interpreter or bundled runtime, attackers frequently package Python code into standalone executables using tools such as PyInstaller. This allows Python malware to be deployed more easily across environments while maintaining cross-platform compatibility. From a defensive perspective, Python-based malware tends to be noisier and more detectable through behavioral analysis, but its prevalence remains high due to its low development barrier.

Rust has seen rapid adoption in modern malware development, particularly among ransomware operators and advanced threat actors. Its design emphasizes memory safety and performance, reducing the likelihood of crashes or instability during execution. Rust binaries are statically compiled and often lack easily recognizable patterns, making them more difficult to reverse-engineer than malware written in traditional languages.

Attackers leverage Rust to produce highly efficient and resilient malware capable of operating across multiple platforms. The relative immaturity of reverse-engineering tooling for Rust further increases analysis complexity for defenders. As a result, Rust is increasingly associated with high-impact campaigns, including ransomware families and custom backdoors, and is viewed as an emerging trend in sophisticated threat development.

Go, also known as Golang, is increasingly used to develop cross-platform malware due to its static compilation model and robust networking capabilities. Malware written in Go can be easily compiled for Windows, Linux, and macOS from a single codebase, making it highly attractive for large-scale or opportunistic attacks. Go is frequently used in ransomware, botnets, and command-and-control infrastructure.

The language’s built-in concurrency features allow malware authors to efficiently manage multiple tasks such as encryption, network communication, and lateral movement. Go binaries are typically large and contain nontraditional execution patterns, which complicates static analysis. As cloud and container environments become more common targets, Go-based malware is expected to continue increasing in prevalence.

PowerShell and Bash are commonly used in fileless malware and post-exploitation activities, particularly during the later stages of an attack lifecycle. These scripting languages are often abused in “living-off-the-land” techniques, where attackers leverage legitimate system tools to avoid detection. PowerShell is especially prevalent in Windows environments, while Bash is widely used on Linux systems.

Threat actors favor these languages because they are typically preinstalled, require no additional binaries, and can be heavily obfuscated. Scripts written in PowerShell or Bash are frequently used for reconnaissance, credential harvesting, persistence, and lateral movement. While scripting-based malware may lack the sophistication of compiled payloads, it remains highly effective due to its stealth and ease of deployment.

C# and the broader .NET framework are commonly used for developing malware that targets Windows environments. The language offers a balance between development speed and access to Windows APIs, making it popular for malware such as remote access trojans (RATs), credential stealers, and loaders. Many commodity malware families rely on C# due to its ease of development and strong tooling support.

Although .NET binaries can often be decompiled, attackers frequently employ obfuscation techniques to hinder analysis. C# malware also integrates well with PowerShell and other Windows-native technologies, enabling seamless execution and persistence. As a result, .NET-based malware remains a staple in phishing campaigns, malware-as-a-service offerings, and financially motivated threat activity.

Although there are many different types of languages that can be used and different ones to use in different situations. Complicated exfiltration through large tech-stacks may involve complicated methods of obfuscation, and therefore more than one language - or others will be require simple C&C servers.