Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bd78cf52df7f159…

MALICIOUS

PDF

12.1 KB
MD5: d0e06ba093be069f184ad5c09139942c SHA-1: a61a7520b53ad7958ec3f06160a4571f912d8ba4 SHA-256: 4bd78cf52df7f159eeb28d63d1de1099fa01fc661f972ed5484cb6271d0fe449
186 Risk Score

Malware Insights

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

The PDF exploits CVE-2007-5659 using a JavaScript stager embedded within an annotation subject. This stager is heavily obfuscated but ultimately decodes and executes further JavaScript. The ClamAV detection 'Pdf.Exploit.Agent-36063' and the heuristic 'CVE_2007_5659: Collab.collectEmailInfo' strongly indicate the exploitation of this known vulnerability. The primary function appears to be the execution of a secondary payload via the embedded and deobfuscated JavaScript.

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
341dd557ae61bccb62e3892eec7849bb4b98b59135623ea39f70dee1e15bd016
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5101 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
934ae697d98750d056558e219fe549ffb27e51ef3c914058d92566758dda7647
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12238 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
e530a2134ec6ef0159aa6cca208ffc49fee317b7b9e08ed46e7823e6799884a9
deobfuscated-js PDF JavaScript deobfuscation pass 76764 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).