Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1051dab1fed20bf…

MALICIOUS

PDF

12.3 KB
MD5: a7730cfe26ac9077ce293ece12bbe192 SHA-1: ad1c759b0c0d94f2ba041bbf9e95597ff7e6a366 SHA-256: b1051dab1fed20bf2af4e78d56d2269949081d91792b9ef11b1533086c80bacf
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, triggered by the CVE-2007-5659 vulnerability via the `collab.collectEmailInfo` method. This JavaScript is heavily obfuscated and appears to be a stager, as indicated by the heuristic `PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER` and the presence of multiple deobfuscated JavaScript files. The primary function of this script is to download and execute a second-stage payload.

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
0bd8a3e7488b8e2fff7dfb9fb3aed2263471d68f407adfc979b93f6c7f03c88d
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5319 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
7eb588c50397154ec38f6fec6b15627c6a6ade1dfeb560ff1dde9e6c1ffbf5c2
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12637 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
5e6ed0016ffdaadbcf3ad5921b477bfd7a0cf5b827da78c24bb93e9a1bfb2fdd
deobfuscated-js PDF JavaScript deobfuscation pass 73701 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).