Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6725897ee8c4095…

MALICIOUS

PDF

96.8 KB Created: 2021-09-17 15:53:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3b01411fca1424f71a440c421ef0a6d4 SHA-1: 35791f899f0d0270c2a8318ffceeccf5060ac325 SHA-256: b6725897ee8c4095ae6c87ee3ad6cbccbd5920c93c68247510b71fa6d32e07aa
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was identified as malicious by ML classifiers and ClamAV, with a critical heuristic flagging it as Pdf.Phishing.Trojan. It contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm designed to obscure the ultimate destination. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically indicates this behavior, aiming to deceive users into clicking through to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://hbisan.com/userfiles/file/88435663814.pdf In PDF document text
    • https://mchs.kz/userfiles/File/23821034920.pdfIn PDF document text
    • http://nagymester.com/userfiles/file/wonep.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/161341dc88f4e0---wowiruxuburadopumuteniso.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca70b0ccc0---81679680559.pdfIn PDF document text
    • http://asacnfservices.com/ckfinder/userfiles/files/mofodejulefagozexi.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/21834607568.pdfIn PDF document text
    • https://nakatarikaszel.pl/app/webroot/userfiles/file/72476491637.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/15146238223.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/41753680823.pdfIn PDF document text
    • http://gevenschoenen.nl/ckfinder/userfiles/files/lalopizefopakiximemu.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/dbb42e99b9faf10f4040dda97e5effda/bozisozejewovu.pdfIn PDF document text
    • https://qian-ho.com/upfiles/editor/files/worinugo.pdfIn PDF document text
    • http://cck-brno.cz/ckfinder/userfiles/files/lajupusevizitesafaxale.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/mopagodidobaleguxav.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/34083177089.pdfIn PDF document text
    • https://nbretail.com.vn/ckfinder/userfiles/files/vetegegesugozezi.pdfIn PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/21843720044.pdfIn PDF document text
    • http://net-marketing.hu/images/files/pazususupawajax.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/kuwudomikupenodutis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=probability+and+statistics+for+machine+learning+pdfPDF link annotation
    • http://louisiana-arts.org.s150269.gridserver.com/siteuploads/editorimg/file/81706414577.pdfIn PDF document text
    • 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_off00010fbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FBB 19548 bytes
SHA-256: 4d1cda9a4fdaedbadddfb892ebea23df7b2a5c89f3b4ea92068abc648c1a9eb6
font_01_sfnt_off000142ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142AD 11320 bytes
SHA-256: d1706c3683d3ddd51b535511027a393cbb0e2785b37a366e8d061848149daed8
font_02_sfnt_off00015cb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15CB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1