Malicious PDF — malware analysis report

Static analysis result for SHA-256 8433538b8162ab27…

MALICIOUS

PDF

87.4 KB Created: 2021-09-24 07:19:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: e6e053320493d77bf2bf28f1bbbb490b SHA-1: 071af61e206456f79d610b94c3baf216cd442455 SHA-256: 8433538b8162ab274ae9d86a02f31cf326898577f2974d71acd697a12e792dfa
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs hosted on compromised WordPress sites and other domains. These links likely lead to further malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612f38e580250---purekejov.pdf In PDF document text
    • https://www.lipca.com/ckfinder/userfiles/files/bulifel.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/pimuvozodoro.pdfIn PDF document text
    • http://entrackintl.com/uploads/sesasoxu.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146ff8a846fc---xabufidasurolik.pdfIn PDF document text
    • http://ledseoul.com/userData/board/file/xebosexanuzabidozoduba.pdfIn PDF document text
    • http://nutricount.cz/UserFiles/File/zabilixokodivoza.pdfIn PDF document text
    • https://epiphanych.com/images/file/patubatubidu.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/8888ea2bec41f8a7e4c2e843c05d27ce/91000728707.pdfIn PDF document text
    • https://papersacksfactory.ae/images/bulk_images/files/naxazapixoli.pdfIn PDF document text
    • http://rancholasmonturaspremios.com/campannas/file/sexuxore.pdfIn PDF document text
    • https://emons-verlag.com/testarea/cwsCMSlight/media/files/kuxomeboj.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/wagalixoxowotalajasudebu.pdfIn PDF document text
    • http://roberlo.cz/www/files/file/somaboraru.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1614b1040b0f67---61797552303.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/79697601730.pdfIn PDF document text
    • http://darangyi.com/userData/board/file/24826098973.pdfIn PDF document text
    • https://rugsinc.in/UserFiles/files/paxivogiririzezanu.pdfIn PDF document text
    • http://shimamura-mail-order.com/userfiles/file/wufopesisewolij.pdfIn PDF document text
    • http://www.temaricerca.com/entry2013/admin/ckfinder/userfiles/files/tuviwaloripigibaridap.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d8ee62808e---nusisifoboropazeva.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161405daf9a0e6---fugifasujen.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=fire+hd+8+androidPDF 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_off0000f217.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF217 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010a2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A2E 10220 bytes
SHA-256: 9718f3c49aad4f3c679b3fbcadfc11d8c7421301e2112ca1973cb15db9f6ece4
font_02_sfnt_off000120f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F8 18264 bytes
SHA-256: b1f11dc12dc53a351c3d53cc905853d4ce9210408fee3ceba3c1da8322ba1118