Malicious PDF — malware analysis report

Static analysis result for SHA-256 37315bdeff5dd55b…

MALICIOUS

PDF

76.2 KB
MD5: 4ca9dce6f48e6b3e01fa83daac09672a SHA-1: e098cd2a7dff5281addb93e1f6d657c8aa09e5bd SHA-256: 37315bdeff5dd55b8dd60d48db6b820e4b295d2e6238c9ee1a49dea7434bcab2
216 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is obfuscated using binary XOR encoding. This script leverages the CVE-2007-5659 vulnerability (Collab.collectEmailInfo) in Adobe Reader to execute a second-stage payload. The script's intent is to download and execute further malicious code, indicated by the use of eval() and String.fromCharCode, and the recovery of a binary XOR decoded JavaScript stager.

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)
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution
  • 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.
  • Suspicious extracted artifact high 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.
  • String.fromCharCode medium PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0004_000.js
42b549627f8adfa0522f3d438ba02c32fc0268a611ccffa17b9655d0c1c4200a
pdf-javascript-stream PDF /JS object 4 at offset 0xC0 77722 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).
binary_xor_stage_000.js
9f2e93d9307bbfd4bba986d31eaac349e5fa7226a29722c25c7db7004b08045c
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3D7 1273 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).