Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4a1223abf2f367f…

MALICIOUS

PDF

11.8 KB
MD5: c06896214571e4e4797b24cec8c4e3d5 SHA-1: cac4c8d46a4ba0e16edb40b7ca245637da57e734 SHA-256: b4a1223abf2f367fe7c0d87087888db716fa01df65ce9e2b3b1d0f70d700d07d
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, identified by multiple heuristics including PDF_JAVASCRIPT and PDF_JS. A critical heuristic, CVE_2007_5659, indicates the use of the Collab.collectEmailInfo method to launch a JavaScript stager. This stager is responsible for downloading and executing a second-stage payload, as suggested by the presence of deobfuscated JavaScript files and the ClamAV detection signature 'Pdf.Exploit.Agent-36063'. The attack pattern involves exploiting a PDF reader vulnerability to achieve code execution.

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
c49b38e11b76a0f1a96a1f8dd4ec5edd337185e3c6e2e99307a5844b89c769df
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5003 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
d7411fc43200f4b7e5a051d985ae822034e758e2f127255b318c09b14145422a
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 11996 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
8c5972f17ddb45f52932e1b64c98de1e62ce8b00e975bcf7cd3be0d5063645f8
deobfuscated-js PDF JavaScript deobfuscation pass 70938 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).