Malicious PDF — malware analysis report

Static analysis result for SHA-256 22a3890dd8d8ec81…

MALICIOUS

PDF

12.1 KB
MD5: cee2d88428513e2acb5464a0f9453614 SHA-1: 4437eb7190c74cf5447cfb41eca2b82a1e8f1bed SHA-256: 22a3890dd8d8ec818fd8790e0133c7f33637fd82af47cb28897ec6e73ce6e9e5
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, triggered by the CVE-2007-5659 vulnerability using the 'collab.collectEmailInfo' method. This JavaScript is heavily obfuscated and decodes into a larger payload. The primary function appears to be the execution of this decoded script, likely to download and run a second-stage payload. The ClamAV detection 'Pdf.Exploit.Agent-36063' further confirms its malicious nature.

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
1c889d389a754bab6a821493846eac8428f11c67c13f0e6318a404cf4e5749a3
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5169 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
eb3a5e4e80a11a67d4e008b65eaac9f4c3ea492728c9ae51acfeefd8ea35613e
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12265 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
2b871b359fbde30bb11e8a1f03d8cc2b7e6db7b7c5accfd4d21b35fbf5d45bad
deobfuscated-js PDF JavaScript deobfuscation pass 83778 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).