AI-Powered Espionage Campaign Targets Government Linux Infrastructure Palo Alto Networks' Unit 42 identified a campaign, tracked as CL-UNK-1211, that targeted government entities and state-affiliated infrastructure with AI-generated payloads between October 2025 and April 2026. The attackers focused on Linux environments, deploying open-source tools, custom cross-platform backdoors and web shells to dump databases and exfiltrate government mailboxes, while disabling endpoint protections, erasing system logs and planting deceptive red-team markers to disguise the intrusion as a legitimate security assessment. Unit 42 said the artifacts contained AI-made conversational annotations and developer reasoning comments, indicating the code was generated by large language models or executed by an automated AI agent, and attributed the cluster to UNK because its affiliation with nation-state or cybercrime activity is undetermined. Unit 42 identified a campaign targeting government entities and state-affiliated infrastructure, with observed activity spanning from October 2025–April 2026. We track this activity as CL-UNK-1211. In the operations we witnessed, the attackers relied on AI-generated payloads. Multiple artifacts deployed throughout the intrusion contained AI-made conversational annotations and developer reasoning comments, suggesting that the code was either generated using large language models LLMs or executed by an automated AI agent. The attackers behind this cluster of activity focused on Linux environments to conduct extensive reconnaissance and maintain persistent network access to support intelligence-gathering. The attackers attempted to dump sensitive databases and exfiltrate government mailboxes to access social media accounts. The campaign included a diverse toolkit that combined open-source tools, custom cross-platform backdoors and widespread web shell deployments. We observed various defense evasion techniques, including attempts to disable endpoint protections, erase system logs and plant deceptive red-team markers to disguise activity as a legitimate security assessment. Our attribution of this activity to CL-UNK-1211 is in accordance with the Unit 42 attribution framework https://unit42.paloaltonetworks.com/unit-42-attribution-framework/ . We designate the term UNK to clusters of activity whose affiliation with either nation-state or cybercrime activity we have not yet determined. This investigation uncovers the defining tools, techniques and attack patterns of this activity cluster. 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If you think you might have been compromised or have an urgent matter, contact the Unit 42 Incident Response team https://start.paloaltonetworks.com/contact-unit42.html . | Related Unit 42 Topics | AI https://unit42.paloaltonetworks.com/tag/ai/ , Credential Harvesting https://unit42.paloaltonetworks.com/tag/credential-harvesting/ , Linux https://unit42.paloaltonetworks.com/tag/linux/ | Our analysis of the CL-UNK-1211 cluster of activity reveals a versatile operational playbook tailored to enterprise Linux and database environments. The attackers targeted government entities and state-affiliated infrastructure, maintaining persistent access by using a combination of custom cross-platform backdoors, open-source utilities and widespread web shell deployments. The attackers enumerated mailboxes to identify and gain access to social media accounts tied to government email addresses. In addition, they dumped entire database contents before attempting to exfiltrate the data. The attackers behind CL-UNK-1211 exhibited a methodical approach to defense evasion. This included attempting to disable endpoint protections on compromised systems, and to tamper with system logs that might contain evidence of the attack. We provide a comprehensive analysis of the defining tools, techniques and procedures TTPs used throughout the operation, highlighting how the attackers leveraged AI to streamline payload creation across their execution workflow. Our analysis details key mechanisms across the attack chain. These include: - Initial access via web shell deployment and credential harvesting - Custom RAT execution - Mailbox targeting - Anti-forensics measures Throughout the operation, the attackers relied on malicious PHP and shell scripts to maintain persistence, perform reconnaissance and exfiltrate data. These payloads revealed structural patterns and artifacts consistent with AI-assisted code generation. Rather than standard developer documentation, multiple scripts contained conversational, step-by-step reasoning notes. These notes explained the code’s logic to the operator who provided the initial instructions. Their presence suggests that the code was either copied directly from an AI prompt output or deployed by an automated AI agent. In addition, we identified several common characteristics that are consistent with AI-operated attacks, such as: - Section headers in scripts and shell commands, which AI uses to analyze the output faster - Extensive use of Base64-encoded commands - Seamless switching between different technologies throughout the attack, including PHP, JavaScript, Bash and Python Figure 1 shows snippets of code from scripts used by the attackers that contained AI-generated comments. To gain access and maintain a persistent backdoor into the host networks, the attackers deployed a variety of web shells on the targeted Linux servers. These were a combination of custom and open-source web shells found on GitHub. Figure 2 shows interactive web shell activity from the php-fpm parent process. To achieve persistence, the attackers modified the auto prepend file value across all PHP configurations under the directories /etc/php/ and /opt/plesk/php/. These directories store all default PHP configuration files and Plesk https://www.hostinger.com/tutorials/what-is-plesk/ web hosting control panel configuration files. Any file that is specified in the modified auto prepend file value will automatically load and execute before any other PHP script runs. In one instance, the attackers deployed a malicious PHP web shell as a file named /usr/lib/php/plesk sys driver.php to appear legitimate. They also modified the auto prepend file to load the malicious web shell to ensure persistence. Figure 3 shows the attacker-deployed PHP script, including the original inline comments. The attackers used multiple methods to gather credentials in the targeted environments, including: - Editing the .bashrc file - Inserting malicious lines of code into PHP scripts - Scanning the network for cleartext passwords The attackers replaced the .bashrc https://www.digitalocean.com/community/tutorials/bashrc-file-in-linux file with a copy containing a malicious command that steals victims’ passwords. In one instance, they created an alias for the sudo command that was designed to execute each time a user attempted to run it. The malicious command: - Displays a prompt for the user to insert their password mimicking the standard system authentication prompt - Captures the inserted password - Writes it to the attackers’ log file The harvested password is then passed to the legitimate sudo command for execution, leaving the victim unaware of the underlying interception. The attackers named the log file Solarwinds.StatusLog.txt, to mimic legitimate SolarWinds activity in the environment. We have no evidence of SolarWinds systems and infrastructure being compromised during this operation; the attackers misused the organization’s name as an evasion method. Figure 4 shows the command hijacking technique inside the .bashrc file. The attackers inserted a line of code into a PHP login page — most likely targeting a database authentication routine — to harvest admin credentials. If an administrator logs in, the code forwards the username and password to the attackers’ log file. Figure 5 shows a snippet of a PHP script including the code added by the attackers. The attackers searched for email, SMTP and database passwords inside configuration files and command history files. Figure 6 shows an example of commands that the attackers used to search for cleartext passwords. The attackers deployed a custom-developed, multi-platform remote access Trojan RAT written in Go, first observed under the benign file name sys-control-client. We named this malware SysGoRAT. This malware supports cross-platform execution on Windows and Linux and employs multiple persistence methods to maintain long-term access. The malware established a command and control C2 connection over WebSocket to wss://