Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a117ceeb43fede1…

MALICIOUS

PDF

466.8 KB
MD5: dc500493ad6428a38defe42ea37017f3 SHA-1: 281939ba8899fca8a66b67a221f4ab4e5bc2d663 SHA-256: 5a117ceeb43fede1b690c8dbf23f9f7f71e436e0c98128f5c51ce10e303065cb
86 Risk Score

Malware Insights

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

The critical heuristic firing for CVE-2007-5659 indicates the PDF exploits a known vulnerability in Adobe Reader. This exploit is used to execute embedded JavaScript, as evidenced by the PDF_JAVASCRIPT and PDF_JS heuristics. The extracted JavaScript files (legacy_pdfkit_stage_000.js and legacy_pdfkit_stage_001.js) are likely responsible for downloading and executing a second-stage payload, a common technique for initial access and further infection.

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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
f048286b2dfe205330e162117bc9e2e9406092389e25aa91660890d79cb205b6
pdf-javascript-stream PDF /JS object 5 at offset 0x106 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 0xEFBF 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 0xEFBF 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).
font_00_sfnt_off0007043b.bin
2722878b19761e7a433e1ca6f32e7f9fe9cccce4136877b3beb9040f23bd4b18
pdf-font-stream PDF embedded font (sfnt) at offset 0x7043B 23432 bytes