2. The Commercialization Phase: Banking Trojans (2013 – 2015)
As Linux desktops gained adoption, cybercriminals began porting Windows-style information-stealing capabilities to Linux architectures.
- Hand of Thief (2013): Recognized as one of the first sophisticated, commercially sold Linux desktop banking trojans. Rather than running in the kernel, it targeted the user space. It heavily exploited the X11 / Xorg server’s lack of application isolation, using global hooks to function as a form grabber and keylogger to specifically capture online banking credentials typed into Firefox or Chrome.
- Linux.BackDoor.Xunpes.1 (Early 2016): A specialized piece of spyware that researchers found targeting retail point-of-sale or specialized hardware (such as Bitcoin ATMs running Linux). It was configured as a classic backdoor with explicit commands to silently trigger JPEG screenshots and log system input data.
3. The Cross-Platform Spyware Shift (2016 – 2018)
Attackers started using cross-platform development frameworks to infect Windows, macOS, and Linux concurrently with the exact same capabilities.
- Backdoor.Mokes (2016): Written in C++ using the Qt framework, this malware family targeted multiple operating systems. Once executed on Linux, it automatically dropped monitoring loops that collected screenshots and captured global keystrokes, saving the data silently to the /tmp/ directory before uploading it to a command-and-control (C2) server.
- MiKey (2016): Discovered by researchers as a tightly optimized, low-detection Linux keylogger ported alongside Windows backdoors. It relied on reading native keyboard event structures directly out of the user session environment.
4. Modern Desktop Espionage (2019 – Present)
Modern strains focus on social engineering to blend into desktop environments or hide inside software supply chains.
- EvilGnome (2019): An advanced piece of Linux desktop spyware designed to masquerade as a legitimate GNOME desktop shell extension. It contained specific functional threads called "Shooters". The ShooterDisplay module utilized Cairo graphic libraries to continuously capture desktop screenshots, while other modules recorded audio from microphones.
- Quasar Linux / QLNX (Recent): A Linux adaptation of the well-known Quasar system administration tool repurposed as malware. Recent samples found in software supply chain attacks feature dedicated internal command IDs (such as 0xA2 for instant screen capture and 0xB0 for triggering live keyloggers via /dev/input or the X11 framework).