Malicious PDF — malware analysis report

Static analysis result for SHA-256 91d3ec2de181a693…

MALICIOUS

PDF

6.6 KB
MD5: f91496eed66e7c41ed5611d59f6503a5 SHA-1: 774d7c607f93e7f3dbf58113431a27d85f12307e SHA-256: 91d3ec2de181a693c5b39dfcb0d22c8cf47caf96c20c5f75d09c0285d54b7a51
268 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 PowerShell

This PDF file contains embedded JavaScript and exploits the CVE-2009-0658 vulnerability, which is a known Adobe Reader JBIG2Decode heap-spray exploit. The ML classifier strongly indicates maliciousness. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 8

  • 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.
  • 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
c4ccfeda39dfbb1f42fcd36566bbcdda18f11f79e27f758d3fe996825a084342
pdf-javascript-stream PDF /JS object 6 at offset 0x225 5032 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).