Androxgh0st is a growing concern in the cybersecurity landscape, first identified in April 2022. This Python-based malware takes advantage of vulnerabilities in popular web development frameworks like Laravel to execute remote code, extract sensitive credentials, and target .env files—repositories often containing crucial environment variables for cloud services like AWS, Office 365, SendGrid, and Twilio. By creating botnets and exploiting known security gaps, Androxgh0st enables activities such as data theft, cryptocurrency mining, and unauthorized use of system resources.
This blog provides an overview on the Androxgh0st's methods, including its exploitation techniques and Tactics, Techniques, and Procedures (TTPs), as well as its broader organizational impact. Finally, it provides actionable strategies (as well as IOCs) to mitigate this persistent threat effectively.
Androxgh0st, first identified in April 2022, is a Python-based malware that has swiftly become a significant threat by exploiting vulnerabilities in widely used web applications and services. Its precise targeting of high-value cloud service frameworks suggests possible connections to organized cybercrime groups or state-sponsored entities aiming for data theft and system exploitation.
The malware primarily targets known vulnerabilities in popular frameworks, notably those in Laravel-based applications. It exploits flaws such as CVE-2017-9841, CVE-2018-15133, and CVE-2021-41773, which allow for remote code execution or unauthorized access. This approach demonstrates the developers' technical sophistication and their ability to leverage systemic weaknesses to infiltrate targets.
A key characteristic of Androxgh0st is its evolution into a botnet that systematically scans for and exploits vulnerable networks. It persistently targets .env files to harvest sensitive credentials, showcasing its adaptability and capacity for sustained impact [1]. The malware's design enables seamless scalability, allowing it to quickly pivot as defenses improve.
Androxgh0st further intensifies its threat profile by extending its reach to cloud services, including AWS and Microsoft Office 365 [2]. This strategic expansion into cloud infrastructure security places it among the most notable active threats. Its ongoing presence in cybersecurity threat reports underscores its significance, with agencies like the FBI, CISA, and leading security firms consistently issuing alerts and recommending robust mitigation measures. The persistent threat of Androxgh0st highlights the necessity for proactive defense strategies and continuous exposure management practices.
Here are the technical details of Androxgh0st malware, focusing on its exploitation of vulnerabilities, botnet-driven scanning, credential harvesting through .env files, and sophisticated defense evasion techniques.
The Androxgh0st malware exploits specific vulnerabilities to execute arbitrary code and gain unauthorized access:
PHPUnit Vulnerability (CVE-2017-9841): Androxgh0st exploits this flaw by sending malicious HTTP POST requests to the /vendor/phpunit/phpunit/src/Util/PHP/eval-stdin.php endpoint, allowing remote code execution on vulnerable websites using PHPUnit. (Note that adversarial scanning for this vulnerability has skyrocketed in 2024 [3].).
Laravel Framework Vulnerability (CVE-2018-15133): The malware scans for exposed .env files in Laravel applications to harvest credentials. If the application key is accessible, attackers can encrypt PHP code and execute it remotely by exploiting a deserialization vulnerability in Laravel's cross-site request forgery (CSRF) tokens.
Apache HTTP Server Vulnerability (CVE-2021-41773): Androxgh0st targets Apache HTTP Server versions 2.4.49 and 2.4.50, exploiting a path traversal flaw that allows access to files outside the document root. If Common Gateway Interface (CGI) scripts are enabled, this can lead to remote code execution.
Androxgh0st malware leverages a botnet-driven approach to conduct systematic, automated reconnaissance across the internet, targeting Laravel applications and their exposed .env files. These configuration files often inadvertently store sensitive credentials for cloud services like AWS, Google Cloud, and Office 365, making them a key asset for attackers seeking unauthorized access.
The malware’s scanning methodology is comprehensive, employing HTTP GET requests to the /.env URI as a primary strategy. If GET requests fail, it escalates to POST requests, embedding the "androxgh0st" identifier in the payload to bypass standard defenses. This dual-layered scanning ensures that even misconfigured or partially secured systems are identified and flagged for exploitation.
Once vulnerabilities are confirmed, Androxgh0st capitalizes on the .env files’ exposed data. These files frequently contain critical credentials, such as access keys and secrets for cloud providers. In the case of AWS, for example, compromised credentials can allow attackers to manipulate cloud resources, deploy new instances, create users, and alter permissions without raising immediate alarms. This capability not only facilitates deeper infiltration but also enables long-term data exfiltration and covert operations within the targeted environment.
By combining its botnet's wide reach with efficient scanning and credential harvesting techniques, Androxgh0st demonstrates a sophisticated and adaptable threat model, exploiting even high-traffic regions and leaving compromised systems vulnerable to prolonged exploitation.
Androxgh0st employs sophisticated evasion techniques to operate stealthily within compromised systems:
Use of Legitimate Credentials: By extracting sensitive data from exposed .env files, Androxgh0st gains access to credentials for cloud services like AWS, Azure, and Google Cloud, as well as database login details. This allows the malware to authenticate as a legitimate user, enabling actions such as launching EC2 instances, altering IAM policies, or accessing S3 buckets without detection. This tactic complicates detection efforts, as security operations centers (SOCs) often rely on credential-based access patterns to verify user authenticity.
Obfuscation of Scripts: According to CISA’s advisory, the malware employs obfuscation techniques, including Base64 encoding combined with complex encryption algorithms, to encode PHP scripts [4]. These scripts are decoded just-in-time during execution, evading static analysis. Moreover, as stressed before, Androxgh0st targets vulnerabilities in web frameworks like Laravel, exploiting Cross-Site Request Forgery (CSRF) tokens, specifically manipulating the XSRF-TOKEN cookie to pass encrypted payloads in GET requests. This allows the malware to insert and execute malicious code that appears benign to intrusion detection systems, leveraging remote file upload capabilities to maintain persistence and evade detection.
Persistence via Web Shells: Androxgh0st deploys web shells—small scripts that offer remote command execution—embedding them in commonly accessed directories on web servers, often masquerading as legitimate files like index.php or admin.html. To ensure these shells remain undiscovered, the malware modifies file permissions and manipulates timestamps, complicating forensic analysis.
Exploitation of Known Vulnerabilities: The malware exploits unpatched systems by targeting well-documented vulnerabilities in popular software stacks, such as those in Apache server configurations or outdated Laravel libraries. This approach often masquerades as routine software update tasks, reducing the likelihood of raising alerts during security audits. By exploiting vulnerabilities listed in public CVE databases, Androxgh0st takes advantage of organizations' reliance on outdated systems or delayed patch management protocols, providing a window for malicious actors to access privileged environments without suspicion.
Dynamic Infrastructure: Androxgh0st leverages compromised AWS credentials to automate the deployment of new virtual machines and user accounts. This includes actions like creating new users, assigning administrative privileges, and deleting original access keys to maintain operational stealth. By swiftly shifting operations across new virtual environments, the malware evades detection by network monitoring tools and frustrates investigative efforts targeting persistent threats.
Botnet Utilization for Distributed Actions: Androxgh0st employs a network of infected machines to perform distributed tasks such as DDoS attacks or cryptomining. Each bot in the network is tasked with small, discrete operations, minimizing the risk of detection. By dispersing its activities globally, the malware blends into normal internet traffic, making it difficult for network heuristics to flag anomalies.
Through these sophisticated evasion techniques, Androxgh0st operates stealthily within compromised systems, making detection and mitigation challenging for security professionals.
The Androxgh0st malware exhibits a wide-ranging set of Tactics, Techniques, and Procedures (TTPs) that align well with the MITRE ATT&CK framework. Below is a comprehensive mapping and explanation of these TTPs, detailing how Androxgh0st employs each technique in its operations:
T1595.002 Active Scanning: Vulnerability Scanning
Androxgh0st performs large-scale scanning operations targeting websites for exploitable vulnerabilities. Leveraging its botnet infrastructure, the malware focuses on vulnerabilities in common frameworks and services, such as PHPUnit RCE (CVE-2017-9841) and Apache Struts flaws, to gain unauthorized access. The scanning is automated, using hardcoded user-agents and custom scripts, to target .env files in Laravel frameworks, webshell vulnerabilities, and exposed API credentials. By employing distributed bots, Androxgh0st minimizes detection risks and ensures redundancy in its reconnaissance efforts. These scans form the foundation for launching targeted attacks, including data exfiltration, cryptojacking, or privilege escalation.
Additional Context:
Here are the HTTP User-Agent strings known to be used by the Androxgh0st malware:
T1583.005 Acquire Infrastructure: Botnet
Androxgh0st leverages its botnet to automate reconnaissance, vulnerability scanning, and exploitation. Each compromised machine in the botnet operates independently to identify potential targets, executing small, distributed tasks to evade detection. This infrastructure enables Androxgh0st to launch sustained exploitation campaigns, including DDoS attacks, credential harvesting, and webshell deployment. The botnet's decentralized design reduces the likelihood of detection while increasing operational resilience.
Additional Context:
T1583.006 Acquire Infrastructure: Web Services
Using compromised AWS credentials, Androxgh0st establishes new cloud instances to serve as infrastructure for its operations. This includes creating new user accounts, assigning administrative roles, and deploying instances for tasks such as cryptocurrency mining, vulnerability scanning, or as Command and Control (C2) servers. The automation of AWS API calls—like CreateUser, AttachUserPolicy, and DeleteAccessKey—ensures that operations can be swiftly established and moved to evade detection.
Additional Context:
T1190 Exploit Public-Facing Application
Androxgh0st exploits known vulnerabilities such as CVE-2017-9841 (PHPUnit Remote Code Execution) and CVE-2021-41773 (Apache Path Traversal and RCE) to gain initial access to systems. By targeting public-facing applications, it injects and executes arbitrary PHP code, providing attackers with a foothold on the compromised server. These exploits are particularly effective on misconfigured or unpatched systems, enabling attackers to bypass authentication mechanisms and manipulate server-side functionality.
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curl --data "<?php <malicious_payload>;" http://<target_ip>/vendor/phpunit/phpunit/src/Util/PHP/eval-stdin.php |
Additional Context:
T1059.006 Command and Scripting Interpreter: Python
Androxgh0st leverages its Python-based scripts to automate a wide range of malicious operations. This includes scanning for exposed .env files in frameworks like Laravel, parsing sensitive credentials (e.g., AWS keys), and establishing unauthorized connections. Python’s versatility enables Androxgh0st to dynamically adapt its behavior, facilitating tasks such as encryption, credential brute-forcing, and API abuse.
Figure 1. AWS key generator/brute force [1].
Key Actions:
Example Indicators:
T1078 Valid Accounts
Androxgh0st exploits stored credentials, such as AWS keys and API tokens, to maintain persistent access. By leveraging legitimate session management systems, the malware avoids raising immediate security alerts. This persistence tactic ensures that even after initial compromises are mitigated, the attacker can continue accessing systems without requiring re-exploitation.
T1505.003 Server Software Component: Web Shell
Androxgh0st installs malicious web shells on compromised servers to enable continuous access and remote command execution. These web shells act as lightweight backdoors, providing attackers with a versatile tool to maintain control over the infected systems.
Key Characteristics:
T1136 Create Account
Androxgh0st uses compromised AWS credentials to create new user accounts with administrative privileges. This tactic ensures long-term access to cloud environments and supports further operations, such as deploying new virtual machines or conducting reconnaissance.
Key Actions:
Example Indicators:
T1027.010 Obfuscated Files or Information: Command Obfuscation
To evade detection, the malware encrypts PHP code segments which are then executed as values embedded in tokens, particularly within Laravel applications. This approach bypasses conventional scanning that alerts to unencrypted malicious code.
T1552.001 Unsecured Credentials: Credentials in Files
Androxgh0st actively scans for unsecured .env files in web application directories, particularly those used by frameworks like Laravel. These files often contain sensitive credentials such as API keys, database credentials, AWS keys, and other access tokens. Once acquired, the malware uses these credentials to expand its reach within the compromised environment, enabling actions such as privilege escalation, cloud infrastructure abuse, and lateral movement.
Additional Context:
T1083 File and Directory Discovery
Androxgh0st conducts file and directory discovery using path traversal attacks, such as CVE-2021-41773 in Apache. By exploiting these vulnerabilities, the malware accesses directories outside the standard root directory, uncovering sensitive files and configurations. This information is leveraged to identify further exploitation opportunities or to exfiltrate valuable data.
Key Tactics:
T1046 Network Service Discovery
Androxgh0st uses its botnet to perform automated network scanning activities, identifying open ports, running services, and configurations within a target network. This allows attackers to map the network infrastructure and pinpoint exploitable services or vulnerabilities.
Key Actions:
T1114 Email Collection
Androxgh0st exploits APIs and email-related applications to harvest sensitive communications and stored credentials. By leveraging credentials acquired from .env files or other misconfigured storage locations, the malware accesses email systems to extract information such as account details, password reset links, and sensitive organizational correspondence. This tactic is often a precursor to phishing campaigns or further exploitation of compromised accounts.
Key Tactics:
T1105 Ingress Tool Transfer
Androxgh0st facilitates the transfer of malicious files by executing PHP code via HTTP POST requests. This technique allows the malware to download and deploy additional payloads, such as webshells, cryptominers, or privilege escalation tools, from remote Command and Control (C2) servers. The use of C2 infrastructure ensures sustained interaction with infected hosts, enabling continuous updates and control.
Key Actions:
Here are the known IOCs for the Androxhgh0st malware.
Incoming GET and POST requests to specific URIs:
Incoming POST requests containing specific strings:
HTTP User-Agent strings:
Additional URIs used for credential exfiltration:
URIs targeted for web shell deployment:
To effectively detect and mitigate the Androxgh0st malware, organizations should implement the following strategies:
Detection Strategies:
Monitor HTTP Requests: Regularly inspect incoming GET and POST requests to specific URIs, such as /vendor/phpunit/phpunit/src/Util/PHP/eval-stdin.php and /.env. Be vigilant for POST requests containing strings like [0x%5B%5D=androxgh0st] or ImmutableMultiDict([('0x[]', 'androxgh0st')]).
Analyze User-Agent Strings: Identify and scrutinize HTTP User-Agent strings associated with Androxgh0st, including variations of Boto3/1.24.x Python/3.10.5.
Review Access Logs: Examine logs for unusual access to URIs used for credential exfiltration, such as /info, /phpinfo, and various .env file paths.
Mitigation Strategies:
Apply Security Patches: Ensure all systems are updated to address vulnerabilities like CVE-2017-9841, CVE-2018-15133, and CVE-2021-41773. Regular patch management is crucial to prevent exploitation.
Restrict Access to Sensitive Files: Configure servers to deny public access to .env files and other sensitive configurations. Implement strict access controls to protect these files.
Disable Debugging Modes: Ensure that live Laravel applications are not in "debug" or testing mode, as these can expose sensitive information.
Remove Hardcoded Credentials: Eliminate cloud credentials from .env files and revoke any that were previously stored. Utilize secure methods for managing credentials, such as environment variables or dedicated secrets management tools.
Conduct Regular Security Audits: Perform routine scans of the server's file system for unrecognized PHP files, especially in directories like /vendor/phpunit/phpunit/src/Util/PHP/.
Monitor Outgoing Requests: Keep an eye on outgoing GET requests to file hosting sites (e.g., GitHub, Pastebin) that access .php files, as these may indicate malicious activity.
By implementing these detection and mitigation strategies, organizations can enhance their defenses against Androxgh0st malware and reduce the risk of compromise.
In conclusion, Androxgh0st represents a sophisticated and evolving threat to cloud and web security, leveraging vulnerabilities in widely used frameworks to execute targeted attacks. Its focus on .env files for credential harvesting, combined with botnet-driven scalability and advanced evasion techniques, makes it a formidable challenge for organizations. The malware's ability to exploit cloud services and integrate seamlessly into compromised environments underscores the need for proactive defenses.
By implementing robust patch management, monitoring for Indicators of Compromise (IOCs), and strengthening security configurations, organizations can mitigate the risks associated with Androxgh0st. Continuous exposure management and threat intelligence are vital to staying ahead of such persistent threats, ensuring resilience against this and other advanced cyber threats.
[1] L. Labs, “AndroxGh0st - the python malware exploiting your AWS keys.” Available: https://www.lacework.com/blog/androxghost-the-python-malware-exploiting-your-aws-keys
[2] S. Gatlan, “FBI: Androxgh0st malware botnet steals AWS, Microsoft credentials,” BleepingComputer, Jan. 16, 2024. Available: https://www.bleepingcomputer.com/news/security/fbi-androxgh0st-malware-botnet-steals-aws-microsoft-credentials/
[3] M. Heath, “Huge Increase in Scanning for CVE-2017-9841 With Large Variability in Scanning Infrastructure,” F5 Labs, Jul. 25, 2024. Available: https://www.f5.com/labs/articles/threat-intelligence/sensor-intel-series-top-cves-june-2024
[4] "Known Indicators of Compromise Associated with Androxgh0st Malware," Cybersecurity and Infrastructure Security Agency CISA. [Online]. Available: https://www.cisa.gov/news-events/cybersecurity-advisories/aa24-016a