Malicious PDF — malware analysis report

Static analysis result for SHA-256 257b02bf24707255…

MALICIOUS

PDF

822.0 KB
MD5: a89095439df6e94c3af8e11ff1ad4a26 SHA-1: a1817d8e586e200aa736d9e7628df3535519ba9b SHA-256: 257b02bf2470725548f239830ecfa2c4ee192737a81d605ba3d33f3ef3ddd9d2
158 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.002 Spearphishing Attachment

The file is a PDF containing embedded JavaScript, with heuristics indicating the use of eval() and unescape() for obfuscation. The ClamAV detection 'Pdf.Exploit.Agent-18493' strongly suggests exploitation of a known PDF vulnerability. The embedded JavaScript is likely responsible for downloading and executing a secondary payload, which is a common technique for initial access and further infection. No specific family could be identified from the available evidence.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-18493 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-18493
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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.
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0052_000.js
45fea71ee6347153ec3719ebc3910509cd6fa568f263c29e7474c694308f5c7d
pdf-javascript-stream PDF /JS object 52 at offset 0x3F4E 301 bytes
javascript_obj0059_001.js
28d6113dc29ef94de179a1345b6983a9d947da00c945e958d0554de4748a5164
pdf-javascript-stream PDF /JS object 59 at offset 0x6483 2612 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 3 long base64-like blob(s).
stream_005_off00000b74.bin
e4217c167299ac63f64b8b7e903cc0196f0828693d273431b8b793a12ed0fed3
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xB74 1000 bytes
objstm_0053_00.bin
f9797d0fa28384c30d8bf1da89163104ce539753e417fa1f9c5fd135d1eceb39
pdf-objstm-decoded PDF /ObjStm 53 0 obj (inflated) 50 bytes