Malicious PDF — malware analysis report

Static analysis result for SHA-256 a69a19efa1ba9e0a…

MALICIOUS

PDF

4.4 KB
MD5: 465cc8a8366915041e525164706c418b SHA-1: fda0dac86b89a267981d84f48e832e1468bb6cee SHA-256: a69a19efa1ba9e0a51c671bd39cda00bacfb213cab67b1579e5e1a9a3a0cea50
146 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The presence of `eval()` and `String.fromCharCode` suggests obfuscated JavaScript code is being executed. The embedded artifact `javascript_obj0005_000.js` is likely responsible for the malicious activity. The JBIG2Decode filter with active content indicators further points to exploitability within the PDF structure. The overall intent appears to be the execution of a malicious script, likely for downloading further malware.

Heuristics 8

  • JBIG2 + active content high CVE related PDF_JBIG2_ACTIVE_CONTENT
    JBIG2Decode appears with JavaScript/XFA/RichMedia — a related indicator for JBIG2 parser-exploit families including CVE-2021-30860 and CVE-2009-0658, but not a unique CVE fingerprint.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • JBIG2Decode filter medium PDF_JBIG2
    JBIG2 image decoder present — historically used in zero-click exploits
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
90078e6604799e1946e44a9453e58f38e845767341b824f5babf698569ef4750
pdf-javascript-stream PDF /JS object 5 at offset 0x10D 23167 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).