Malicious PDF — malware analysis report

Static analysis result for SHA-256 206c55fdfd0de3d4…

MALICIOUS

PDF

8.6 KB
MD5: 9c1535885b8a923cb4bfec2fcaf16406 SHA-1: 6ebe7807ccdc107b9b8eb9668f276bf9f839a8c1 SHA-256: 206c55fdfd0de3d4c410f94bc097f7e81ee575feb5067d7b570c4c509967b316
94 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is obfuscated using String.fromCharCode and other techniques. The critical heuristic firing indicates exploitation of CVE-2007-5659 via the Collab.collectEmailInfo method, which is used to execute JavaScript. The extracted JavaScript streams suggest the intent is to download and execute a second-stage payload. No specific family could be identified due to the generic nature of the exploit and obfuscation.

Heuristics 6

  • 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)
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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. (identified after JavaScript deobfuscation)
  • 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_obj0004_000.js
8b70e431ed36d84945464549cd8184fb5a7cf6ee13d19263f40a1485872c8893
pdf-javascript-stream PDF /JS object 4 at offset 0xE1 2105 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
numeric_charcode_stage_000.js
9d5c7e01faed5b04e9ec11f1d98b73f0012c871beaf60e9f9d32ad6df00d46f7
deobfuscated-js numeric char-code string decoded JavaScript at offset 0xEF 550 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
c59c0c830f7cf16cf9f89fa70e2c8094b9238d71af214e212227942d5e19ef31
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1CDE 1813 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
9d3a2fc01abd1c7193e147e8f6710a99f60057da280b11dffad04da983b8f4c5
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x4D0 5189 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).