Malicious PDF — malware analysis report

Static analysis result for SHA-256 a656cde542d2c366…

MALICIOUS

PDF

12.2 KB
MD5: f3f85c3c08f2f7d297dbfc9d9560f2dd SHA-1: 5cbd44aeb4d4996e41c7eef587207903c53ffe0a SHA-256: a656cde542d2c366c247a94ea234ccd3eb92a94547729c305f076a2dc87ed6dd
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is obfuscated and designed to be executed by a PDF reader. The critical heuristic CVE_2007_5659 indicates the exploitation of a vulnerability related to `Collab.collectEmailInfo` and a hex decoder, commonly used to stage further malicious activity. The ClamAV detection further confirms its malicious nature. The primary attack vector appears to be exploiting a known PDF vulnerability to download and execute a secondary payload.

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
25e7b3b14d1408e371d46f6122dd4e3fb290404d112d950b841fc3b184cded6e
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5240 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
e15bce3c78236176f5bc30dce25753343581e69690ff4da60f15d9912720cdff
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12464 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
d0611384082ae1ea0b94f45fda330586061e2d2a4e8cbb5703b0120a58b5933d
deobfuscated-js PDF JavaScript deobfuscation pass 77599 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).