Malicious PDF — malware analysis report

Static analysis result for SHA-256 98e5217aa39c2b93…

MALICIOUS

PDF

12.1 KB
MD5: b10ac2fa533f5a69d311f353fa448c7c SHA-1: a508f067b7e01ff1d32e103502e8212bd648bdd7 SHA-256: 98e5217aa39c2b9343dcd6fd1d10071d523df0d8b6008dc9105ee6b8f65c886a
186 Risk Score

Malware Insights

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

The PDF file contains multiple embedded JavaScript streams and triggers heuristics related to JavaScript stagers and the CVE-2007-5659 vulnerability (Collab.collectEmailInfo). The primary attack vector appears to be the exploitation of a PDF reader vulnerability to execute obfuscated JavaScript. This script likely acts as a downloader for a second-stage payload, as indicated 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
e733c79e15a62a6b4f115d7d8896973f60b499d0d8513e9f142f7412042e11cb
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5161 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
60768b06026333eeb96e5f55bfc47077122ad177fe1e418c67d98b0232806202
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12241 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
179726c6b01e96ff116297d04c6139a80ac18337f606f1e6d31ba315e419b6dc
deobfuscated-js PDF JavaScript deobfuscation pass 78789 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).