Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad20d84c17a8eb06…

MALICIOUS

PDF

11.9 KB
MD5: a8331a00fdc4d188fd0e55b41fbd6fa3 SHA-1: 1c48e00d32e0ef730a7d627a09c3e64ca3027995 SHA-256: ad20d84c17a8eb06017f22a8209d5518d63b0379ab5b4e271bdbee545e20839e
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, specifically leveraging the CVE-2007-5659 vulnerability through the Collab.collectEmailInfo function. This JavaScript is heavily obfuscated and appears to act as a stager, indicated by the heuristic 'PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER' and the presence of multiple deobfuscated JavaScript files. The ClamAV detection 'Pdf.Exploit.Agent-36063' further confirms its malicious nature. The primary attack vector is the exploitation of a PDF reader vulnerability to execute arbitrary code.

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
991607b55bd82a54e95ac9bbd736e3ab7c6115bf35fd7e67471d9e707ee8f206
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5084 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
1667b9fca1bee3280cbf21611f65dc78b8476285adcb87a90f0453d537604014
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12100 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
09c8da85952be447214c06511485e3339d11b89d5fe910c89fa7e074bba7acdc
deobfuscated-js PDF JavaScript deobfuscation pass 77285 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).