Malicious PDF — malware analysis report

Static analysis result for SHA-256 531cd3fb257896da…

MALICIOUS

PDF

98.8 KB Created: 2021-08-13 11:43:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4517907282e524e1bb4da0c4821a763f SHA-1: 7364d93add6ca41ab11d6fe276facafdc7d09c46 SHA-256: 531cd3fb257896da98f1e48d8a1e8addc3de246793dc4114eb802e7308694055
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs, many of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of numerous links suggests a link farm designed to obscure the ultimate destination or to leverage compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/hungaesag4ook25650a9260oaq/supusojiwur.pdf In PDF document text
    • http://anupbolivia.com/images/files/tofatupelif.pdfIn PDF document text
    • http://sequirk.ie/userfiles/file/ruzizuguxidemegigepu.pdfIn PDF document text
    • http://dohertylaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/66085912645.pdfIn PDF document text
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/3bomoavs7t169u9bq1t75fseok/fejijejevedapol.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160814e3ece604---70736165140.pdfIn PDF document text
    • http://artbaget.net/admin/ckfinder/userfiles/files/babodafumawuretigexoduzos.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d74f99e293---74718978612.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc4ed2b9d3---76678919537.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160947d79bb170---3500573761.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160aa0a8bbffbf---faxatexal.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/66411171208.pdfIn PDF document text
    • http://donghobaoan.com/uploads/files/82678549452.pdfIn PDF document text
    • https://rhagro.com.mx/wp-content/plugins/super-forms/uploads/php/files/83c3a23d82c3dcc3386dc891ec7d9d77/61102245807.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/zufekiwoxedobukumulubasu.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/pazefupegubomanazunoxu.pdfIn PDF document text
    • http://drthchowdary.net/userfiles/file/godokosedoxafabid.pdfIn PDF document text
    • https://wccia-vastu.com/wp-content/plugins/super-forms/uploads/php/files/19a02c0725b2d876fad4bd58d6fdc43d/49605453053.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/30698ed374d6d13214570f7de3fa6b03/67378921191.pdfIn PDF document text
    • http://gentlemensquartersbarbershop.com/wp-content/plugins/super-forms/uploads/php/files/7161a68b637158c22c3a4b57e9663754/gawoderuborelugadodinudo.pdfIn PDF document text
    • https://dpt-mh.com/uploads/news/files/petajafatedegelewa.pdfIn PDF document text
    • http://pixel-pro.ru/upload/file/91780126777.pdfIn PDF document text
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/bogosejojofos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=proyecto+de+investigacion+cualitativa+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_off0001175e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1175E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012f70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F70 19388 bytes
SHA-256: ec4dbb05a4faa3ddc0b3ca0e372d99a14c87396c7cef7b44329cf10fd6388999
font_02_sfnt_off000160b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x160B6 11076 bytes
SHA-256: 47cf7ac5b08cfeae084ba0e24426b859769b59fcdaf742105bb1ea0e222a848c