Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1587e508c557c6f…

MALICIOUS

PDF

78.2 KB Created: 2021-06-17 04:29:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 91f0b645bae66d2e2c6c770d661cd174 SHA-1: cdcfcf319b90324da1e2de194ce7ff1a42dad909 SHA-256: a1587e508c557c6fb4ff945ea54035be3a69fcdf9945ce853fd8d44a31300d6e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the presence of embedded URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest the document's primary purpose is to facilitate the distribution of further malicious content or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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://allytemp.ru/uplcv?utm_term=strategic+human+resource+planning+is PDF link annotation
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/73fe0d09aa3b6078ac274ec201b284c7/fepekofasoboped.pdfIn PDF document text
    • http://dentish.ru/ckfinder/userfiles/files/zasorumewilidizogawipe.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ebaf4acd90---nugizilufikuve.pdfIn PDF document text
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607d8004acf59---736185879.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078ba696d14c---japovinusus.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16079024be52c4---bokiziputirixilanozevamu.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16098fd78a11e7---govalivezelinobisexisod.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/k41bhds2ukou446a4c2i8sn992/46632936977.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a5aec1be30a---karunasoxiwow.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/f7be8751e636394150bbf1128b3bfa8f/99395067178.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/ad97d5d032741e1bdf482907b018ac15/misaburinapowajodimo.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/936d80d8d9ea80d0613e9f2c5ae1c893/3794969538.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160757c527948c---91538830197.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16088eae1040f2---detusomajixuposolabeloto.pdfIn PDF document text
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/45434175059.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/zewuwolifitoges.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f6be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6BE 5448 bytes
SHA-256: ce80a8c6792bd8658233b594b1c1982af4d3e9649e94b92c6670fcb347b9dc26
font_01_sfnt_off0001091c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1091C 10204 bytes
SHA-256: 04dc4dbeba0114b05a88190a7e329de312df2d2b529feeb65504d0cc9272deb7