Justice AV Solutions (JAVS) Viewer Installer Embedded Malicious Code Vulnerability

Added to KEV
2024-05-29
Federal due date
2024-06-19
Vendor
Justice AV Solutions
Product
Viewer
EPSS
94.2th percentile (score 0.128, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2024-4978

CISA short description

Justice AV Solutions (JAVS) Viewer installer contains a malicious version of ffmpeg.exe, named fffmpeg.exe (SHA256: 421a4ad2615941b177b6ec4ab5e239c14e62af2ab07c6df1741e2a62223223c4). When run, this creates a backdoor connection to a malicious C2 server.

Required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.