Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e50e228a77ec4e7…

MALICIOUS

PDF

12.0 KB
MD5: 10c41f4c786e3007de441a84f3cbd409 SHA-1: 0229798fde1cea491f988a457a0327d9b3c7d67a SHA-256: 4e50e228a77ec4e7335dbdf102ee2fee01e2c9af3f6bfb1ac63a216696c36acb
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Scripting T1204.002 Malicious File

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. A critical heuristic, CVE_2007_5659, specifically identifies the use of the Collab.collectEmailInfo method to launch a JavaScript stager. This stager is likely responsible for downloading and executing a second-stage payload, as suggested by the large size of the deobfuscated.js artifact and the ClamAV detection name Pdf.Exploit.Agent-36063. The attack pattern is therefore a PDF exploit leveraging JavaScript to deliver further malicious content.

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 3

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
65b5d91dd4022607faec87a74ebfa50d14d5cb01bdd56e5d5699a7f248db22eb
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5135 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
5b5f7a44b411f57e015b8861f908e8d898239c1b49c2722207758ea6ec6fa4ff
deobfuscated-js PDF JavaScript deobfuscation pass 74719 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).