Malicious PDF — malware analysis report

Static analysis result for SHA-256 ffbf82d358c7f269…

MALICIOUS

PDF

13.2 KB
MD5: 500a42e64ce5284cd1d379c1bdf7e38c SHA-1: fb24e26eea8ebdd8a2bd3411855a45c9349429c7 SHA-256: ffbf82d358c7f26995d579dc1f108a5fa71a753bbc93f0269c7dca71a2bc160b
186 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that exploits CVE-2007-5659 (Collab.collectEmailInfo). The script is XOR-encoded and uses String.fromCharCode to deobfuscate itself, ultimately aiming to download and execute a second-stage payload. The heuristic firings strongly indicate a PDF exploit targeting Adobe Reader.

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
ce28fbea0fdf5bb0b8fcc6f0f5a1f7dcf8945ff91793fb1c173e1d2641471c10
pdf-javascript-stream PDF /JS object 49 at offset 0xA 78088 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
d6dba1c8de836ba78f901733f4f2c0f2199ec3a21be3886bffcb6b3dec79505b
deobfuscated-js binary-XOR decoded JavaScript at offset 0x464 1300 bytes