Malicious PDF — malware analysis report

Static analysis result for SHA-256 f924b08a12bc4b3c…

MALICIOUS

PDF

11.7 KB
MD5: c2770b5147c3bc92efebf8a31c7704c4 SHA-1: 0d89a321081c74ceedb4252c04795880344e6326 SHA-256: f924b08a12bc4b3c71c790d430e4fed2055810e4497ecbe80a7aaf1fd0d26b5d
186 Risk Score

Malware Insights

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

The sample is a PDF file that leverages the CVE-2007-5659 vulnerability through the `collab.collectEmailInfo` function to execute embedded JavaScript. The JavaScript appears to be heavily obfuscated, with multiple stages of deobfuscation indicated by the extracted artifacts. The primary intent seems to be downloading and executing a second-stage payload, as suggested by the presence of multiple deobfuscated JavaScript files and the ClamAV detection signature 'Pdf.Exploit.Agent-36063'.

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
e3529c1b054faa9b2dd29352e5219537485b68512889388d67767f57b8323449
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 4947 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
65a65ac207d7f0d82a1aead6832747440387c8c3176e91a63b1c55ee22bd182c
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 11971 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
6489a8672ac841865371326e8bb5b9b833593a7c306816474bb262bd420963f3
deobfuscated-js PDF JavaScript deobfuscation pass 73923 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).