The U.S. Cybersecurity and Infrastructure Safety Company (CISA) on Thursday launched particulars of two units of malware that had been found in an unnamed group’s community following the exploitation of security flaws in Ivanti Endpoint Supervisor Cellular (EPMM).
“Every set comprises loaders for malicious listeners that allow cyber risk actors to run arbitrary code on the compromised server,” CISA stated in an alert.
The vulnerabilities that had been exploited within the assault embody CVE-2025-4427 and CVE-2025-4428, each of which have been abused as zero-days previous to them being addressed by Ivanti in Could 2025.
Whereas CVE-2025-4427 issues an authentication bypass that enables attackers to entry protected sources, CVE-2025-4428 permits distant code execution. In consequence, the 2 flaws might be chained to execute arbitrary code on a weak system with out authentication.
In accordance with CISA, the risk actors gained entry to server working EPMM by combing the 2 vulnerabilities round Could 15, 2025, following the publication of a proof-of-concept (PoC) exploit.
This permitted the attackers to run instructions that made it doable to gather system data, obtain malicious recordsdata, checklist the basis listing, map the community, execute scripts to create a heapdump, and dump Light-weight Listing Entry Protocol (LDAP) credentials, the company added.
Additional evaluation decided that the cyber risk actors dropped two units of malicious recordsdata to the “/tmp” listing, every of which enabled persistence by injecting and working arbitrary code on the compromised server:
- Set 1 – web-install.jar (aka Loader 1), ReflectUtil.class, and SecurityHandlerWanListener.class
- Set 2 – web-install.jar (aka Loader 2) and WebAndroidAppInstaller.class
Particularly, each units include a loader which launches a malicious compiled Java class listener that intercepts particular HTTP requests and processes them to decode and decrypt payloads for subsequent execution.
“ReflectUtil.class manipulates Java objects to inject and handle the malicious listener SecurityHandlerWanListener in Apache Tomcat,” CISA stated. “[SecurityHandlerWanListener.class] is a malicious listener that intercepts particular HTTP requests and processes them to decode and decrypt payloads, which dynamically create and execute a brand new class.”
WebAndroidAppInstaller.class, however, works in another way by retrieving and decrypting a password parameter from the request utilizing a hard-coded key, the contents of that are used to outline and implement a brand new class. The results of the execution of the brand new class is then encrypted utilizing the identical hard-coded key and generates a response with the encrypted output.
The top result’s that it permits the attackers to inject and execute arbitrary code on the server, enabling follow-on exercise and persistence, in addition to exfiltrate information by intercepting and processing HTTP requests.
To remain protected towards these assaults, organizations are suggested to replace their situations to the most recent model, monitor for indicators of suspicious exercise, and implement obligatory restrictions to stop unauthorized entry to cell system administration (MDM) programs.
