Malicious PDF — malware analysis report

Static analysis result for SHA-256 285266135e4b2402…

MALICIOUS

PDF

12.1 KB
MD5: e4f8e1579ff07e53574dc8106daf8a71 SHA-1: 59cb3bf1344983036111190c55692b84e7e13c60 SHA-256: 285266135e4b24026350d9bdf660a7bb6bf0408dd63a1d9abcea69d8d4a3e5cd
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is obfuscated and designed to act as a stager. Heuristics indicate the use of CVE-2007-5659 (Collab.collectEmailInfo) to exploit a vulnerability, likely for the purpose of downloading and executing a secondary payload. The presence of multiple deobfuscated JavaScript files suggests a multi-stage infection process.

Heuristics 7

  • 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-36063 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36063
  • 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.
  • 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)
  • 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_obj0007_000.js
eb39e2de4dbbc100de6d3e30aa43ff78fa075618862ba1ebba5151ea3a3b848d
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 273 bytes
annotation_subject_callee_hex_stage_000.js
0d3de212c19012919a8ea820819b2daa12087c13e41be44d545d43c163fcc113
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5144 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
a7679bedaa8bfa5f3ae46dfd29024d5f5fa0dac3211e5ff62b9cf1ddef3c07ec
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12171 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
eea71ca8ecfd9f67568ea98b2b41a8660dca0ee185b3983ab8c93ee6036fa3a0
deobfuscated-js PDF JavaScript deobfuscation pass 76597 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).