Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef7557561146eab8…

MALICIOUS

PDF

12.4 KB
MD5: d8524acf1f97e6d5f342d52c19744cb8 SHA-1: 5286389cc20c4902590bfc4702960cec5feb9c72 SHA-256: ef7557561146eab8e1a98af5b980ca0253c3ae1061f112b16e8848831c87ea37
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The critical CVE_2007_5659 heuristic specifically points to the use of the 'collab.collectEmailInfo' method, a known exploit primitive for PDF vulnerabilities. This suggests the file is designed to leverage this exploit to execute arbitrary code or download further malicious content. The presence of multiple deobfuscated JavaScript files indicates a complex, multi-stage execution chain.

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
41215eb5927672e736152f890f91d8ba64bc87716ce8cd933d177409a706f6af
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5281 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
2a2183d8f1b746cf149c6c3ed4f923400114335562ed710b3fcc5937a7d3c028
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12550 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
d7c6cd9901de478b9bf7c8c380afb15156c7f3cdc1de715d9645e6cc565b74a2
deobfuscated-js PDF JavaScript deobfuscation pass 80374 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).