Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a3fcf19b549f5d7…

MALICIOUS

PDF

11.2 KB
MD5: a9ed0bedd479e0fbf2479e271c6dc71f SHA-1: dfc6cd36121d81760b0db1b809bf97aa099288e0 SHA-256: 8a3fcf19b549f5d716d3000b45626112175e39bc6d238553e9f0eafc5801e3b9
126 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, identified by the PDF_JAVASCRIPT and PDF_JS heuristics. Specifically, the CVE_2007_5659 heuristic indicates the exploitation of a vulnerability using the Collab.collectEmailInfo method to execute a hex-encoded JavaScript stager. This stager, recovered as 'annotation_subject_callee_hex_stage_000.js', is responsible for decoding and executing a secondary payload. The presence of obfuscated JavaScript and the exploitation technique strongly suggest a malicious intent to download and run further malicious code.

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)
  • Annotation subject callee-key hex JavaScript stager high PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER
    PDF JavaScript uses syncAnnotScan()/getAnnots() to read an indirect annotation /Subject stream, percent-decodes it through marker replacement, then uses a callee.toString()-derived key to decode and eval the final exploit stage.
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
c860bd3a1b8438b37e98a599719a1868ae540624631f091272ffef48912644f4
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 579 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
annotation_subject_callee_hex_stage_000.js
40e2aac5b2513d1b9564c4a3bff78e0976d93c37c1c9037d1daf33c11c3119a3
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 4898 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).