Malicious PDF — malware analysis report

Static analysis result for SHA-256 730a96f9b2f6c910…

MALICIOUS

PDF

7.0 KB
MD5: e97f5b2bfd02f86b34579f10c769ea73 SHA-1: 7499a3a891c02958d362c87d3ee3e6e1b15ba753 SHA-256: 730a96f9b2f6c91003ec63747aeefdd319adcc43196f3d586c37534ec8ccd0e2
388 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file contains obfuscated JavaScript code that leverages the unescape function, a common indicator of exploit activity. The heuristics indicate a successful exploitation of CVE-2009-0658, a known vulnerability in Adobe Reader's JBIG2Decode filter, which is used to execute arbitrary code. The embedded JavaScript is designed to download and execute a secondary payload, as evidenced by the exploit cluster and ML classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 10

  • Adobe Reader JBIG2Decode generic heap-spray exploit critical CVE likely CVE_2009_0658_GENERIC_SPRAY
    PDF combines JBIG2Decode image streams with JavaScript heap-spray or decoder scaffolding. This is likely CVE-2009-0658-family Adobe Reader JBIG2 exploitation, but it lacks the stricter Reader-9 version gate or decoded page-word shellcode fingerprint required by the exact rule.
  • JBIG2 + active content high CVE related PDF_JBIG2_ACTIVE_CONTENT
    JBIG2Decode appears with JavaScript/XFA/RichMedia — a related indicator for JBIG2 parser-exploit families including CVE-2021-30860 and CVE-2009-0658, but not a unique CVE fingerprint.
  • Hex-obfuscated scripting name object critical PDF_OBFUSCATED_NAME_OBJECT
    A PDF name object that drives script execution (/JavaScript or /JS) is written with #XX hex escapes to hide it from string-based scanners — e.g. /J#61v#61S#63r#69p#74 decoding to /JavaScript. Legitimate PDF producers always write these names literally; hex-encoding an executable name is a deliberate evasion used by exploit-kit and dropper PDFs.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • ClamAV: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • JBIG2Decode filter medium PDF_JBIG2
    JBIG2 image decoder present — historically used in zero-click exploits
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
c8ee3eaeedee317e66586ad70b85244fd332f2f18c387315713a0b98842b2985
pdf-javascript-stream PDF /JS object 6 at offset 0x21B 5376 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).