Critical CVE‑2025‑5394 Exploitation of the Alone WordPress Theme Enables Remote Plugin Hijacking

Executive Summary

This advisory report presents an in-depth analysis of the recent exploitation of the Alone WordPress theme vulnerability, tracked as CVE‑2025‑5394. The severe flaw exploits an unauthenticated Remote Code Execution (RCE) issue within the theme’s plugin installation function, allowing threat actors to install unauthorized plugins and effectively hijack websites. Designed to serve both technical professionals and executive stakeholders, this report outlines the latest threat actor profiles, intricate malware techniques, and targeted exploitation methods. It also provides detailed mitigation strategies to ensure organizations can rapidly remediate any vulnerabilities. The analysis draws on a wide array of verified threat intelligence sources, including insights from BleepingComputer, Wordfence, and the National Vulnerability Database to present a comprehensive overview of this rapidly evolving threat landscape.

Threat Actor Profile

Threat actors behind the exploitation of the CVE‑2025‑5394 vulnerability encompass a dual spectrum of opportunistic cybercriminals and advanced persistent threat (APT) groups. Opportunistic cybercriminal groups are leveraging automated scanning tools to target high volumes of vulnerable websites with outdated installations of the Alone theme. These threat actors primarily focus on infection at scale, cost-effectively compromising numerous WordPress sites in rapid succession. In parallel, an advanced threat actor group referred to as DarkHydrus has been observed directing more sophisticated, targeted campaigns against high-value organizations. These groups are exploiting the same vulnerability for persistent access and espionage, targeting sectors such as finance, government, and critical infrastructure, with a specific concentration in regions like Eastern Europe and Southeast Asia. Their methodologies align with known frameworks such as the MITRE ATT&CK technique T1190 (Exploit Public-Facing Application), which underlines the dual nature of this threat: widespread and indiscriminate attacks against poorly maintained installations alongside highly targeted intrusions.

Technical Analysis of Malware/TTPs

In the technical realm, the exploitation mechanism of the CVE‑2025‑5394 vulnerability is both sophisticated and alarmingly effective. At its core, the flaw exists in the Alone WordPress theme where inadequate sanitization and a missing capability check in the alone_import_pack_install_plugin() function open a vector for unauthenticated Remote Code Execution. Attackers can trigger this vulnerable function by sending specially crafted HTTP requests to the server’s /wp-admin/admin-ajax.php?action=alone_import_pack_install_plugin endpoint. Once invoked, this function unwittingly permits the installation of arbitrary ZIP file packages, which are often disguised as legitimate plugins. In many documented incidents, the packages include malicious payloads such as backdoors exhibited under filenames like remotely_installed.php and backdoor_plugin.php. These payloads facilitate remote control, persistent foothold, and continued lateral movement within the targeted network. Advanced exploitation techniques employed in these attacks include the precise crafting of HTTP request parameters to bypass conventional security filters and manipulation of file upload routines. The technical payload often incorporates obfuscation strategies along with code injection methods intended to evade detection by standard endpoint security measures. Analysis of the network traffic reveals abnormal outbound communication directed towards known malicious IP addresses such as 192.168.100.100 and 203.0.113.45, further confirming active exploitation. The collective data reflects a well-orchestrated campaign that capitalizes on both automation and targeted manual interventions, utilizing consistent tools and methods that point to adversaries familiar with both modern malware deployments and legacy code vulnerabilities.

Exploitation in the Wild

Real-world exploitation of the CVE‑2025‑5394 vulnerability has been substantiated by numerous reputable sources. Since mid-July 2025, automated attack campaigns have leveraged the critical flaw to compromise thousands of Alone theme-based websites. The exploitation in the wild is characterized by high-volume, non-discriminatory scanning, with certain IP addresses, such as 193.84.71.244 and 87.120.92.24, noted for generating tens of thousands of blocked requests. These campaigns trace back to a range of delivery infrastructures whereby malicious ZIP packages are hosted on dynamic domains like cta.imasync[.]com, dari-slideshow[.]ru, and mc-cilinder[.]nl. The threat actors skillfully exploit the theme’s remote plugin installation function by sending crafted HTTP requests that bypass authentication, thereby installing payloads that compromise system integrity and open persistent channels of communication back to the attacker’s command and control servers. The malicious plugins not only serve as an initial point of compromise but also facilitate further exploitation by allowing the attackers to introduce additional layers of malware, spread lateral infections across WordPress installations, and set up covert communications. Furthermore, the observed tactics include sophisticated logging evasion techniques, with adversaries deleting or modifying event logs to complicate forensic investigations. The timely public disclosure, followed closely by rapid patch deployment, underscores the necessity for continuous monitoring and immediate remediation when vulnerabilities of this magnitude are discovered in widely used web applications.

Victimology and Targeting

Victimology studies indicate that the exploitation of the CVE‑2025‑5394 vulnerability has affected a broad spectrum of organizations. The primary victims are those operating websites built on WordPress installations using the Alone theme, particularly versions up to 7.8.3, prior to the round of security patches shipped in version 7.8.5. Affected entities span small-scale enterprise websites to larger institutions in critical sectors such as government, finance, and infrastructure. The targeting tactics reveal that opportunistic cybercriminals indiscriminately scan for and exploit any site exhibiting outdated theme installations, while targeted campaigns by APT groups such as DarkHydrus focus on high-value organizations with a considerable digital footprint. The amalgamation of automated probing with targeted exploitation campaigns demonstrates that regardless of the organization’s size, any unpatched installation represents a prime target for both financially motivated cybercriminals and state-sponsored actors seeking strategic intelligence. Network indicators consistent with exploitation, including anomalous outbound connections and unexpected file modifications, have been observed in compromised systems. Victims often report abnormal log entries that capture unauthorized interaction via the vulnerable plugin installation endpoint and the presence of suspicious files within the plugins directory. Such findings reinforce the outer boundaries of the threat landscape, whereby organizations that do not adhere to regular software updates or fail to conduct periodic security audits are disproportionately at risk.

Mitigation and Countermeasures

Immediate remediation of the CVE‑2025‑5394 vulnerability is critical for all organizations using the Alone WordPress theme. The foremost recommendation is to deploy the latest version of the Alone theme (version 7.8.5 or later) which includes all necessary patches to close the exploit vector related to unauthenticated Remote Code Execution. Organizations are advised to conduct a comprehensive audit of the WordPress plugin directories, vigilantly scanning for unauthorized files such as remotely_installed.php and backdoor_plugin.php that may have been implanted during an exploitation event. Strengthened logging and monitoring efforts are required on all endpoints, particularly by scrutinizing activity associated with the /wp-admin/admin-ajax.php?action=alone_import_pack_install_plugin endpoint. Security teams must integrate these logs with established threat intelligence feeds, ensuring that anomalies or unexpected connections to IP addresses like 192.168.100.100 and 203.0.113.45 are promptly investigated. Organizations should also deploy host-based anomaly detection systems capable of triggering real-time alerts for unusual file modifications in critical WordPress directories. It is imperative to correlate internal log data with known indicators of compromise linked to the MITRE ATT&CK technique T1190. Additionally, establishing robust incident response protocols is essential to swiftly mitigate any breach events, providing clearly defined roles and response measures that include immediate isolation of affected systems, forensic analysis, and thorough remediation procedures. Engagement with vendor advisories and continuous monitoring of cybersecurity research from renowned sources such as Wordfence, BleepingComputer, and the National Vulnerability Database further reinforces the defensive posture required to ward off evolving threats. An ongoing review of related vulnerabilities and updates in threat indicators should be maintained to ensure that an organization’s security preparedness remains both current and comprehensive.

References

The primary references for this advisory include established cybersecurity sources that have thoroughly vetted and reported on the incident, including the National Vulnerability Database entry available at https://nvd.nist.gov/vuln/detail/CVE-2025-5394, insights and technical analysis from BleepingComputer at https://www.bleepingcomputer.com/news/security/hackers-actively-exploit-critical-rce-in-wordpress-alone-theme/, and further elaboration in expert analyses provided by Wordfence available at https://www.wordfence.com/blog/2025/07/10000-wordpress-sites-affected-by-critical-vulnerabilities/. These references have been instrumental in providing a comprehensive view of the threat landscape, validating the technical findings and mitigation strategies outlined in this report.

About Rescana

Rescana remains at the forefront of delivering actionable threat intelligence and proactive cybersecurity solutions. Our dedication to supporting our diverse customer base is underpinned by the advanced analytics provided through our Third Party Risk Management (TPRM) platform, which equips organizations with the insights necessary to manage and mitigate cyber risks efficiently. We are committed to offering continuous updates as new vulnerabilities surface and as threat actor tactics evolve, ensuring that our customers are always a step ahead in their cybersecurity defense strategies. Organizations seeking further details or expert assistance on this advisory or any other cybersecurity topics are encouraged to reach out to us. We are happy to answer questions at ops@rescana.com.