Malicious PDF — malware analysis report

Static analysis result for SHA-256 a642394909b48167…

MALICIOUS

PDF

11.8 KB
MD5: 0f3e1457e3111db87ff174ed01ea48ce SHA-1: 9ffe1d1b7f10f58aba6897c0c64f47be68252567 SHA-256: a642394909b48167c15bb52397a1d407be31d31a3250f8f9139ad2f3aa35df57
126 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.001 Malicious Link T1059.003 Windows Command Shell

The PDF exploits CVE-2007-5659 using a JavaScript stager embedded within an annotation's subject field. The critical heuristic 'CVE_2007_5659: Collab.collectEmailInfo' indicates the use of this specific vulnerability. The embedded JavaScript, recovered as 'annotation_subject_callee_hex_stage_000.js', is responsible for decoding and executing further malicious code, likely downloading and executing a second-stage payload. The presence of PDF_JAVASCRIPT and PDF_JS heuristics further confirms the use of JavaScript for malicious purposes within the PDF.

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
6b0b4d2acf5aa536f8ae4e75a373108243f72bffa49814a0ad804945223e9047
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5241 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).