Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3ea9f1eba231e58…

MALICIOUS

PDF

13.0 KB
MD5: 2a5a20549f5f849bc17d6886c2cfa51f SHA-1: 8e9ddcba54c5c1763e7dc69978cb9fe08c33ff8a SHA-256: d3ea9f1eba231e585957760c5730ddf9773527cb196dd7f0d2ebb744739bb904
188 Risk Score

Malware Insights

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

The sample is a PDF document that contains obfuscated JavaScript. The critical heuristic CVE_2007_5659 indicates that the JavaScript exploits a vulnerability in Adobe Reader (Collab.collectEmailInfo). The JavaScript is XOR-encoded and then evaluated, likely to download and execute a second-stage payload. The presence of PDF_JAVASCRIPT and PDF_JS heuristics further supports this analysis.

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: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • Binary-XOR JavaScript stager high PDF_BINARY_XOR_JS_STAGER
    PDF JavaScript stores viewer-version payload branches as long binary digit strings, XORs each bit pair, converts 8-bit chunks with String.fromCharCode, and evals the recovered 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.
  • 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)
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0049_000.js
470cf4d377b4ee0156f0cc9f0217127ca13174e55c129b4086a05a1bdce6352a
pdf-javascript-stream PDF /JS object 49 at offset 0xA 77116 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).
binary_xor_stage_000.js
16c05682a41ee00231b49b0cdcf9b74b36c09e49dcd8049eab28f2ef78598e84
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3F8 1282 bytes