Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dac7b9130b6dace…

MALICIOUS

PDF

93.3 KB Created: 2021-07-23 14:25:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 883a57a023c1e65b06e75193bbe9cd5e SHA-1: e8646f4d0920c88902f30476685cf9970729f678 SHA-256: 4dac7b9130b6dace7551da2472b0b02c0855f4f93ff7158cff04ad74bd9d85ae
96 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which are hosted on compromised WordPress installations. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to manipulate search engine results or distribute malicious payloads indirectly. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/gsj626pg5hltlrbnko3l1deda5/rupimujuju.pdf In PDF document text
    • http://www.bufolari.com/public/immagini/file/63729844139.pdfIn PDF document text
    • http://penney1970.com/clients/7/74/747debde904cce1d9d58e62e9103e361/File/75652464056.pdfIn PDF document text
    • http://phunggia.biz/userfiles/file/jovutibitowojal.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/94570464746.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/16082c234028f4---bobibunafikezav.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/67786301960.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/3419b03efe7988b6ea990164980c1374/kelowilivobidufano.pdfIn PDF document text
    • http://merwepizza.com/upload/file/sojibazipapuxukevipifuj.pdfIn PDF document text
    • http://zovsh.com/Uploadfiles/files/88962924999.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/16078952340e5f---papok.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/g0k3t6s5ftofnf4khl7cirad66/jibutomagejadu.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/8ab6dda9d38ed65baf6b8303e2feae34/874225978.pdfIn PDF document text
    • https://otelnamore.com/wp-content/plugins/super-forms/uploads/php/files/57291dc047d8c4ce94de819e2aa025e3/22116814411.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c92471320a---majipekunikixemumadamupel.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b094458090c---81230881781.pdfIn PDF document text
    • http://mindentudor.hu/userfiles/file/43067097280.pdfIn PDF document text
    • http://guinyardfamilyreunion.com/clients/62985/File/zavaporojuleluxumuvanap.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160732fd766476---41714814303.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/e3277bb36cd19c1d64d924a59af63818/kozajefav.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/bd691056853f89b8841687c7f1fac7df/80408184263.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b22c5b09269---gejutibudusazugofizas.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/45dc1392a13b9de2108eefcb9d363945/vikamuxipobilofuwigofiwe.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/71382040686.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=node.js+design+patterns+-+third+edition+packtPDF 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_off0001081d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1081D 11048 bytes
SHA-256: 0f7f9eeff46447f34ce09fca80f8053ebd554832d16f0869766cc658dfd0fe3c
font_01_sfnt_off0001218a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1218A 17536 bytes
SHA-256: ab4bdad00c2c47ddcaee88996e24e78c3829e7d5d44b8b6db017d1674032c858
font_02_sfnt_off00014ed8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14ED8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1