HTTP: Response is not JPEG/GIF/PNG/BMP
This signature is triggered if a mismatch is detected between the content type "image/jpeg" and the actual data. The signature detects if HTTP response is not starting with JPEG, GIF or PNG magic bytes. Recent malware Command and Control ("C&C") channels use encrypted data with "jpeg" content-type, but they are not well-formed JPEG/GIF/PNG files and will be detected by this signature.
Short Name
HTTP:STC:IMG:NO-JPG-GIF-PNG-BMP
Severity
Minor
Recommended
False
Recommended Action
None
Category
HTTP
Keywords
JPEG/GIF/PNG/BMP Response is not
Release Date
01/19/2015
Supported Platforms
mx-19.3
vmx-19.3
vsrx-19.2
srx-19.3
srx-branch-19.3
vsrx3bsd-19.2
srx-19.4
vsrx3bsd-19.4
srx-branch-19.4
vsrx-19.4
vmx-19.4
mx-19.4
srxevo-25.4
vsrx-26.2
srx-26.2
srx-branch-26.2
vsrx3bsd-26.2
mx-12.3
srx-12.3
srx-branch-12.3
vsrx-12.3
Sigpack Version
3324
False Positive
Occasionally