Malicious PDF — malware analysis report

Static analysis result for SHA-256 9826ea940b73192a…

MALICIOUS

PDF

83.0 KB Created: 2021-09-07 02:04:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: fd7e79d9a7c1211d2e6f9b799a05ce4b SHA-1: 5032ad0b94e788704402246232ce4c26106b02dc SHA-256: 9826ea940b73192a05928f0f57565c6e753125dae3f4a77fd98a8bcd6df4e99c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites that appear to be compromised WordPress installations, serving as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO spam or to host phishing content. The presence of multiple distinct hosts and the use of 'utm_term' parameters suggest an effort to manipulate search engine rankings or distribute malicious content.

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://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160af8972d5d05---1018898002.pdf In PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/48eeaf34f26d8e637b98e8c033062527/pogejade.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/71c34e42172de3bbdb045f618cce7e20/wexojinojozedikinoku.pdfIn PDF document text
    • http://nguyenquangcomputer.com/upload/ck/files/kisaxodudubunanagidaleti.pdfIn PDF document text
    • http://tokstar.com/_UploadFile/Images/file/dibefezagafafomadepifezaf.pdfIn PDF document text
    • http://parejalecaros.com/adjunto/upload/fck/files/lafezilur.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/48968279373.pdfIn PDF document text
    • http://orikon.net/Images_upload/files/7088231306.pdfIn PDF document text
    • http://hopkinshigh1961.com/clients/878968/File/pivapejewawikabavev.pdfIn PDF document text
    • https://sonntag-immobilien.lu/userfiles/files/59264834499.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/e216501544ae6e5713b482d883f32dbd/13317203128.pdfIn PDF document text
    • http://wallsfamilyreunion.com/clients/876683/File/20651927712.pdfIn PDF document text
    • http://slphs66.com/clients/e/e6/e62fa13cff665df70d7481f632b33819/File/36589668706.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160de0219c29d7---suruma.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/80424928056.pdfIn PDF document text
    • http://veiligheidsslot.nl/ckfinder/userfiles/files/11295362544.pdfIn PDF document text
    • https://monyetmesum.com/contents//files/mejojazuw.pdfIn PDF document text
    • http://houstontca.org/Content/uploads/files/67672495960.pdfIn PDF document text
    • http://ankamet.com/userfiles/file/32106806896.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/m16secvp02a95nntrp7npihj6k/25372047821.pdfIn PDF document text
    • http://fhs76reunion.com/clients/0/00/009202203981f132fd14d012a57c0fe5/File/52410046557.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/suwobedupuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=jaybird+bluebuds+x+sport+bluetooth+headphones+manualPDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/815e74b57b07b7576e5e4eaad8470340/64006580974.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_off0000de73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE73 17868 bytes
SHA-256: a5cd327afd7bf2034d44c19299f474f0efa6959882258386b782a89390dd7a07
font_01_sfnt_off00010ca0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000124b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124B7 11104 bytes
SHA-256: 5f79917e1f5b3241c382170419ac38d78ab52e66784845fa7e7e56aa90432140