由于任何人都可以接管被原始作者遗弃的资料库，AUR在其软件包中发现恶意软件。名为xeactor的用户接管了acroread软件包，使Arch Linux用户可以查看PDF文件。从Git提交的源代码中发现xeactor添加了恶意代码，该代码将从ptpb.pw下载一个名为~x的文件，这是一个模仿Pastebin的轻量级站点，允许用户共享小块文本。随后会下载并运行另一个名为~u的文件，用来收集有关每个受感染系统的数据，并使用攻击者的自定义Pastebin API密钥将这些详细信息发布到新的Pastebin文件中。AUR团队表示xeactor用户接管的另外两个软件包中也找到了类似代码，三个软件包的所有恶意更改都已被撤消，xeactor的帐户已被暂停，目前没有观察到任何其他恶意行为。

Malware has been discovered in at least three Arch Linux packages available on AUR (Arch User Repository), the official Arch Linux repository of user-submitted packages.

The malicious code has been removed thanks to the quick intervention of the AUR team.

The incident happened because AUR allows anyone to take over "orphaned" repositories that have been abandoned by their original authors.

On Saturday, a user going by the pseudonym of "xeactor" took over one such orphaned package named "acroread" that allows Arch Linux users to view PDF files.

According to a Git commit to the package's source code, xeactor added malicious code that would download a file named "~x" from ptpb.pw, a lightweight site mimicking Pastebin that allows users to share small pieces of texts.

When the user would install the xeactor package, the user's PC would download and execute the ~x file [VirusTotal, source code], which would later download and run another file named "~u" [VirusTotal, source code].

Besides downloading ~u, the main purpose of the first file (~x) was also to modify systemd and add a timer to run the ~u file at every 360 seconds.

Malware didn't do much

The purpose of the second file (~u) was to collect data about each infected system and post these details inside a new Pastebin file, using the attacker's custom Pastebin API key.

Collected data includes details such as the date and time, machine's ID, CPU information, Pacman (package manager) details, and the outputs of the "uname -a" and "systemctl list-units" commands.

No other malicious actions were observed, meaning the acroread package wasn't harming users' systems, but merely collecting data in preparation for... something else.

There isn't a self-update mechanism included, meaning xeactor would have needed a second acroread package update to deploy more intrusive code, or potentially another malware strain.

Two other yet-to-be-named packages also found infected

The AUR team also said it found similar code in two other packages that the xeactor user had recently taken over. The following packages and versions were known to be affected:

All malicious changes to all three packages have now been reversed, and xeactor's account has been suspended. The AUR repository should not be confused with official pacakges in the Arch Build System (ABS). AUR packages are user generated and submitted to the repository, while ABS packages are official packages from trusted sources. The Arch Linux team has warned users for years about verifying each AUR package before installing it.

https://www.bleepingcomputer.com/news/security/malware-found-in-arch-linux-aur-package-repository/