Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fd84dc3a0a47d03…

MALICIOUS

PDF

9.4 KB
MD5: af7f0d97bd121f31304cdb057b91a87f SHA-1: 2c8bf00a550ab7eb353ac78a3a01af221034e0e0 SHA-256: 3fd84dc3a0a47d0304232695f60e284ce79797cc99b8b01c3c98a45672c2d466
86 Risk Score

Malware Insights

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

The PDF sample contains embedded JavaScript, triggered by the CVE-2007-5659 vulnerability (Collab.collectEmailInfo). The JavaScript streams, particularly 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', are indicative of a downloader or exploit stage. These scripts likely attempt to download and execute a second-stage payload from a remote source, although the specific URLs or final payload could not be reconstructed from the provided evidence.

Heuristics 5

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
f048286b2dfe205330e162117bc9e2e9406092389e25aa91660890d79cb205b6
pdf-javascript-stream PDF /JS object 5 at offset 0x118 916 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
7a590a04ea87350e84c3856974289b971d37449302c9c2940b4de6ef81f0d52b
deobfuscated-js z-percent hex-pair decoded JavaScript at offset 0x3D8 4919 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
79371305d462f00f2a141b476e1cf8fba05bdb49c15d53c9a49ff740e927b262
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x3D8 11601 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).