Malicious PDF — malware analysis report

Static analysis result for SHA-256 66a2ca0a1076feb9…

MALICIOUS

PDF

77.5 KB Created: 2021-09-12 00:06:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: db6733dfca07e7cb92de8a2030a6f1de SHA-1: a8490a591be815749b2077e1e84b348646f017d7 SHA-256: 66a2ca0a1076feb92945f65398784d2da72b7999549f8658e50d436902fcd44f
126 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The PDF contains numerous links to external websites, many of which appear to be part of a link farm. The presence of a 'disposable link farm' heuristic further supports this, suggesting the document's primary purpose is to direct users to a network of sites, potentially for SEO manipulation or to host further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://posicert.com/upload_fck/file/2021-9-2/20210902160200469131.pdf In PDF document text
    • http://jingluo.net/uploadfiles/files/63467336548.pdfIn PDF document text
    • http://nenorm.com/files/files/jememikuxajil.pdfIn PDF document text
    • https://sudhirsachdevaclasses.com/ci/userfiles/files/92962047237.pdfIn PDF document text
    • http://icmasistemas.com/userfiles/files/wugesepeweted.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/ratomer.pdfIn PDF document text
    • https://hilanguage-com-tw.triangle-design.com/files/lutujolavenipudo.pdfIn PDF document text
    • https://jancsoalapitvany.hu/ckfinder/userfiles/files/38323655993.pdfIn PDF document text
    • https://tonymusic.se/UserFiles/files/kikeputegujegi.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/badupobaxabarusofim.pdfIn PDF document text
    • https://melz-feu.ru/upload/nigazesu.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fda6f810d4---18774188121.pdfIn PDF document text
    • http://xn--jt2b56wn0ap2a.com/upload/file/202109090756535620.pdfIn PDF document text
    • https://accounting789.com/ThImg/file/nobubidewisuw.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a488656dc7---85316396846.pdfIn PDF document text
    • https://ijmscr.com/ckfinder/userfiles/files/vesimod.pdfIn PDF document text
    • https://raselapp.com/userfiles/file/pogegalotigigi.pdfIn PDF document text
    • https://pernambucoimortal.com/imagens/files/34303462646.pdfIn PDF document text
    • http://greenbrier101.com/userimages/57696525888.pdfIn PDF document text
    • http://naturallabs.de/userfiles/file/lusurefijumil.pdfIn PDF document text
    • http://akifkasaboglu.com/esatfisek/images_upload/files/1626093605.pdfIn PDF document text
    • https://secolink.sk/userfiles/file/piwusujusemuzi.pdfIn PDF document text
    • http://ues-rb.ru/themes/ues-rb.ru/files/numasituvaxolu.pdfIn PDF document text
    • http://ovstav.cz/app/webroot/files/files/47825312760.pdfIn PDF document text
    • http://spiregene.com/image/files/20210907_141403.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=start+with+why+simon+sinek+free+pdfPDF 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_off0000cb7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB7E 16640 bytes
SHA-256: bbaa6b2fee3a2986fa561f7032dc01cceb24dbfefc84a562992a332e569f0cae
font_01_sfnt_off0000f638.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF638 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E4F 11084 bytes
SHA-256: 9e29c68350a7a25bab8bcf3d2ce8a0ea5db3647661fc9e779ad04a2b332fe949