Malicious PDF — malware analysis report

Static analysis result for SHA-256 ebf2ccbbc1a17174…

MALICIOUS

PDF

8.4 KB
MD5: eb6807e7c257212e932ddcaf3fd595e8 SHA-1: 71c9f22e34868ad237931461e048f90097362ba1 SHA-256: ebf2ccbbc1a17174f5a2e693a194ba45c13a5d2cef09f163b23d69485baaf691
126 Risk Score

Malware Insights

MITRE ATT&CK
T1204.001 Malicious Link/Object: User Execution: Malicious Link T1059.001 Command and Scripting Interpreter: JavaScript/JScript

This PDF file exploits CVE-2007-5659 using embedded JavaScript. The JavaScript is heavily obfuscated using String.fromCharCode and other techniques, but the core functionality appears to be the execution of arbitrary code. The ML classifier strongly indicates maliciousness. The exploit targets a vulnerability in Adobe Reader's annotation handling.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 6

  • 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)
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (identified after JavaScript deobfuscation)
  • 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_obj0004_000.js
be4694a17eb89a55f7eb3db389ba2bc4f102f4c7dcfc99549d848cdb7df5dfb5
pdf-javascript-stream PDF /JS object 4 at offset 0xE1 1940 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
numeric_charcode_stage_000.js
6c41320119e160dc719997b9a2efb3600ea9d7e9d7e44b4dc2125762dc9f365f
deobfuscated-js numeric char-code string decoded JavaScript at offset 0xEF 505 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
929f530db04579c059a9ad694942ebba650b28c2e9b75514e822a169f18d78b9
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1C55 1851 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
13a99d9106d5c81716df2e1fea66a60680acf737f1c7a15a11bf1088c93d08cd
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x4C3 5031 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).