Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a2b4c2ecf93dd9a…

MALICIOUS

PDF

9.6 KB
MD5: 3bfd0a946d37e80ea1c8cbe738c06a23 SHA-1: 7275169d2c4f1a528b5d715acec947c9b0fc953a SHA-256: 7a2b4c2ecf93dd9a7db9b81fd9d043cda453f28d904216049a13a6fabbda923f
304 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF file contains heavily obfuscated JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, PDF_EVAL, and PDF_UNESCAPE. The critical CVE_2007_5659 firing points to the exploitation of a known vulnerability within PDF viewers. The embedded JavaScript, particularly the 'annotation_subject_callee_hex_stage_000.js' and 'deobfuscated.js' artifacts, is responsible for executing the malicious payload. The ClamAV detection of 'Pdf.Exploit.Agent-35912' further confirms its malicious nature.

Heuristics 9

  • 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)
  • ClamAV: Pdf.Exploit.Agent-35912 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35912
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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.
  • Suspicious extracted artifact high 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.
  • 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.
  • 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. (matched in decompressed stream)

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
7218a1c68060953321573daa035b16f5f32928ce25a9eb656690dbe78cd9464e
pdf-javascript-stream PDF /JS object 7 at offset 0x19B 201 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
annotation_subject_callee_hex_stage_000.js
49f11c13a0535581c70e539b490d61d6ad65453659268a2ba7d72e29994830f5
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5230 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
43e6243f899f28f096f1cefb8eec276d1f541eaa292a08b52068a9a665f5af19
deobfuscated-js PDF JavaScript deobfuscation pass 44849 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).