Malicious PDF — malware analysis report

Static analysis result for SHA-256 4235f18bd16d45f6…

MALICIOUS

PDF

78.6 KB Created: 2021-09-06 08:19:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 221b0d2e1f9e3088033ac89b91e9c277 SHA-1: de797987e8e7de5dbc1842a0333f1eda61ab269c SHA-256: 4235f18bd16d45f6ac77fcd05c20f7c4568d95b1ad95a4072a379b586649e8bf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it's a link farm hosted on compromised WordPress sites. Embedded JavaScript is present, likely used to redirect users to malicious URLs. The presence of multiple URLs pointing to potentially compromised or disposable hosting reinforces the phishing and malicious redirection intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://apexhealthnutrition.com/newerac2c/userfiles/file/nanunipagogaleg.pdf In PDF document text
    • http://drwatsonsr.com/clients/2/2b/2b9a0cf27321ceab3a47fbd10bf94d34/File/1411099473.pdfIn PDF document text
    • http://esangsok.com/upfile/files/juwaripujabutogotofi.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e499e156fce---28992469570.pdfIn PDF document text
    • https://elpmarketing.ca/wp-content/plugins/super-forms/uploads/php/files/8782e5ebb1c3acb1a9e055a00d14f5ff/wetifugup.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/72610887471.pdfIn PDF document text
    • http://bowlingkillers.com/imgdb/files/dijebenuninisinimuvisudum.pdfIn PDF document text
    • https://ariconium.cz/webpagebuilder/ckfinder/userfiles/files/30073442176.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16085fc0787b86---lubumipox.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/0afebc3c11cbc5d3427130b65a36d3ee/4202574514.pdfIn PDF document text
    • http://www.dagmarsvendova.cz/admin/js/ckfinder/userfiles/files/gilewabokabikafozowenov.pdfIn PDF document text
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160b4b7128d1c5---55800104799.pdfIn PDF document text
    • http://susutour.com/userfile/file/13000086726.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/7b3fbb983da8762db9fe76c28e3c85af/16565098929.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607c311b437e8---nawupagefulapema.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b1283c29f58---5830488829.pdfIn PDF document text
    • http://minipit.com/data/files/30452546066.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/mesegufodaligiforinopapa.pdfIn PDF document text
    • https://www.hasmow.com.au/application/third_party/ckfinder/userfiles/files/25212279939.pdfIn PDF document text
    • http://virus-safe-zone.com/ckupload/files/jopixusozibabofoxikap.pdfIn PDF document text
    • http://thanhlapcongtykiengiang.com/upload/ck/files/bozeroxakobomorigexejaw.pdfIn PDF document text
    • http://shadesvalleymounties1969.com/clients/868959/File/56472426673.pdfIn PDF document text
    • http://ipea.kr/userData/board/file/86251221643.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/160865690850b2---55128820413.pdfIn PDF document text
    • http://yavuzselimvakfi.org/resimler/site/files/lesewewivufa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=ready+for+cae+book+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_off0000c788.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC788 10496 bytes
SHA-256: 2a7457026f62103209e9ff01e250b9caa76d4f76e33b27e5e1fd7ef18730b0b9
font_01_sfnt_off0000df4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF4A 21252 bytes
SHA-256: 92a1d17cd47401f81735742e1b209d7720531c90b98471203fa4222b4e9f327f
font_02_sfnt_off000114ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1