Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ea29f2aa6255b8b…

MALICIOUS

PDF

13.3 KB
MD5: 73f1a497d8cbe3d0d9b828ef21d18022 SHA-1: d03c499247b710da2351984afe85fdb8d15eeb16 SHA-256: 8ea29f2aa6255b8bbce88453e3a12eb4c7e29d0685781c2a123a97b4f8b43e2a
186 Risk Score

Malware Insights

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

The file is a PDF containing obfuscated JavaScript, identified as a stager for the CVE-2007-5659 exploit targeting Adobe Reader. The JavaScript is binary-XOR encoded and uses String.fromCharCode to deobfuscate further strings. The primary function of the script is to exploit this vulnerability, likely to download and execute a second-stage 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: 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
b3ffe621331ae6145e735bb078fef890c7320a403b6586bbbdae3d80c4b8f139
pdf-javascript-stream PDF /JS object 49 at offset 0xA 78664 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
8f8961e04e6f2bb4f582325346455d636da6a95dc255e36e2912577243662386
deobfuscated-js binary-XOR decoded JavaScript at offset 0x464 1312 bytes