Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a7d9c720edc0c2…

MALICIOUS

PDF

81.4 KB Created: 2021-09-22 16:09:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: bdabe4235946fa184d96ccaa81756979 SHA-1: 4a699dbc47ff3bf2166f54456e715ac2c7d35458 SHA-256: 91a7d9c720edc0c2377b115457ce89b2c50b5e2219fc88221362bc70bde0f46d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of a link farm on disposable hosting and compromised CMS uploads suggests an attempt to obscure the ultimate destination and leverage vulnerable infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 https://smidgel.ru/uplcv?utm_term=save+tiktoks+without+watermark+ios PDF link annotation
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/arfqpbnh7fj01epf96hqv7136j/fagap.pdfIn PDF document text
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/78265b854a8ed158d5b5944ababde665/16294254380.pdfIn PDF document text
    • http://gamax-moto.cz/data/dokumenty/85135129344.pdfIn PDF document text
    • http://satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/tizadami.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/8c0c71f97b1ae9d4ce511a5efd28ba42/5942890999.pdfIn PDF document text
    • http://specimport.by/files/files/tadapixidenefanexaz.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/nusemozomo.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/piravilebejunupuwuxalel.pdfIn PDF document text
    • http://lscapital.it/images/file/11526590891.pdfIn PDF document text
    • http://pitchdecor-construction.com/user_img/files/futovinekiweketixadibiwi.pdfIn PDF document text
    • https://www.utn.ac.cr/sites/default/files/files/45497505302.pdfIn PDF document text
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/18636613489.pdfIn PDF document text
    • https://tenfci.org/userfiles/file/rukoxemesonidijoloja.pdfIn PDF document text
    • http://klm-co.ru/foto/ck/files/73927429965.pdfIn PDF document text
    • https://ncvpte.in/userfiles/file/28590457934.pdfIn PDF document text
    • http://yibetter.com/data/files/xizutosejewex.pdfIn PDF document text
    • https://bisnismedsos.com/userfiles/file/begawufuzanenizaji.pdfIn PDF document text
    • http://xn--90afqerdlt1f.xn--p1ai/admin/ckfinder/userfiles/files/jenujuvimuf.pdfIn PDF document text
    • http://yusungchart.com/userData/board/file/19214593472.pdfIn PDF document text
    • https://aayams.com/userfiles/file/fosajofigexidoz.pdfIn PDF document text
    • http://magic-mugs-factory.com/uploadfile/files/60991197083.pdfIn PDF document text
    • http://saringkarnwood.com/UserFiles/file/34329069167.pdfIn PDF document text
    • http://adhdesign.de/userContent/files/20210908062910-80771172015.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_off0000d9db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9DB 17436 bytes
SHA-256: 699f70571dd0daf4bbef51c85c7ae1b982d8693e15721331e25c2683d8b7e0e0
font_01_sfnt_off00010748.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10748 10644 bytes
SHA-256: 0c75a90ea1fbcd3a283944c181fd47705e75e8ebe963804133cf8ee395b6c8e0
font_02_sfnt_off00011fbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FBE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1