Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6ffbbadc995b926…

MALICIOUS

PDF

11.8 KB
MD5: a39ec18097bf18756a7cc0f842e5ffaa SHA-1: a3056f81a13f3e6c6263f2c248e9f97f2e4582a2 SHA-256: c6ffbbadc995b926e30371de86ea70a446ef0d6f5ebe93519dbd123d9d7e03c3
216 Risk Score

Malware Insights

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

The PDF document contains embedded JavaScript, specifically identified as a stager exploiting CVE-2007-5659 via the Collab.collectEmailInfo method. This JavaScript is heavily obfuscated but is designed to decode and execute further malicious code. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the download and execution of a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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
69434220e9bbaf33c9d18e7db1517b3f55ea41f6bd8beb894128f998d05f396b
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5107 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
944d0b0a8b6ba1a4f1453119a53be9f6da32041bde59f802c21d2497cd52eecc
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12169 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
b95ea28b624c1d9768c0e592a7e2255c6ceeadd6109a8fbb184afddcf0115633
deobfuscated-js PDF JavaScript deobfuscation pass 70730 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).