Malicious PDF — malware analysis report

Static analysis result for SHA-256 537a6e3fe212c6d2…

MALICIOUS

PDF

71.1 KB Created: 2021-10-02 11:20:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 63795aa4031e130ba65bdeed61c14c50 SHA-1: 37ab715a54ef108ff9626b52d2652a9a686f40a9 SHA-256: 537a6e3fe212c6d27b11e55e2ffd63cca4c34b9854d89cb239e957b96202b2e0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or redirecting users to malicious sites. Although no scripts were explicitly extracted, the PDF structure and heuristics suggest it's designed to exploit users by directing them to potentially harmful URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://cuakeobinhduong.com/upload/files/xikilodulalezofobamefelu.pdf In PDF document text
    • https://cordovajewelry.com/images/file/tofewagisivuwizupovib.pdfIn PDF document text
    • https://promtour-rural.ro/userfiles/file/50931887151.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/viduneralez.pdfIn PDF document text
    • https://dudikom.pl/userfiles/file/77254455726.pdfIn PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/kururilobejaleverepulixun.pdfIn PDF document text
    • http://phukhoabacninh.com/images/files/25976018950.pdfIn PDF document text
    • http://carneslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/35395853610.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/91277220126.pdfIn PDF document text
    • http://mondoacquapiscine.com/userfiles/files/tejaw.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d609a59740---narepivawawinimegajem.pdfIn PDF document text
    • http://hondasushi.com/uploads/files/63571357353.pdfIn PDF document text
    • http://esteel.my/userfiles/file/ruguw.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143701370ba7---24862617243.pdfIn PDF document text
    • http://tai-group.com/upload/files/mezelibixokifuwefiropu.pdfIn PDF document text
    • http://veewood.com/file_media/file_image/file/46445715209.pdfIn PDF document text
    • http://bangiyaparishadtoronto.ca/bpt/editor/uploadfiles/51366636976.pdfIn PDF document text
    • https://nasco-ye.com/uploads/file/wajavugoxuzeti.pdfIn PDF document text
    • http://prosefkuchare.cz/userfiles/faxisewoler.pdfIn PDF document text
    • http://viermaalh.nl/Bottesteyn/Site/afbeeldingen/file/robaviwazunokewe.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/bemugumidonikitunor.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/sepadurugofokemapilisaros.pdfIn PDF document text
    • https://camerabentrenet.camerabentre.vn/ckfinder/userfiles/files/besogewojug.pdfIn PDF document text
    • https://amoslodge10-org.alljobsinliberia.com/ckfinder/userfiles/files/51661718215.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=pierre+and+jeanPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b31c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB31C 18260 bytes
SHA-256: 7388c3d6d99b4fcefaea89085e8f97c35d9bbb740e2998450e5de52615e7103e
font_01_sfnt_off0000e145.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE145 9940 bytes
SHA-256: 603ef8f12bb5238b32627ea9a721bb9084a50ecc690e22a3bcf83febbc4d3930
font_02_sfnt_off0000f735.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF735 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1