Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b5078ea62748d58…

MALICIOUS

PDF

88.4 KB Created: 2021-10-16 09:10:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e75b45105f80c282acd76264591d5dd6 SHA-1: 21f249a28e13a5c0846e1a035934aafb8a834c08 SHA-256: 4b5078ea62748d58b88c980360259384b9bad6b7a3645fc36e4bac2a37bb8cda
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as 'Pdf.Phishing.Trojan' and flagged by an ML classifier, indicating malicious intent. It functions as a link farm, containing numerous URLs pointing to potentially compromised websites and disposable hosting, consistent with phishing or malware distribution tactics. The presence of multiple PDF link farm heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://foursservices.com/nbloom/fckuploads/file/66987068506.pdf In PDF document text
    • http://szm.hu/userfiles/file/62586108582.pdfIn PDF document text
    • http://bannails.com/fckeditor_userfiles/file/50698857454.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131766d6d6e9---wonelenapekotewofasudo.pdfIn PDF document text
    • http://mcutech.net/upload/2021/09/file/1632322782625782536.pdfIn PDF document text
    • https://tsegypt.com/file/66139305750.pdfIn PDF document text
    • https://herfection.herfection.tw/upload/ckfinder_temp/files/20211014154556.pdfIn PDF document text
    • https://bustotoronto.com/userfiles/file/subosogusuzun.pdfIn PDF document text
    • https://megacook.pt/site/upload/file/tajug.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1614d243fafca5---silisidena.pdfIn PDF document text
    • https://zenit-npk.ru/files/file/25243703620.pdfIn PDF document text
    • http://www.tsahimmongol.com/uploads/images/files/papurumomaditokofofamumuv.pdfIn PDF document text
    • https://haisanquangninh.org/data/dulieu/files/gowebaxaxenux.pdfIn PDF document text
    • https://mmgrowersg.com/ckfinder/userfiles/files/66640112451.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/52912863985.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/ad131fbd4955f60384e7417e7d14de3c/fugolowudunumitoxidoxalub.pdfIn PDF document text
    • https://calprin.com/ckfinder/userfiles/files/dirinove.pdfIn PDF document text
    • http://quangphong.vn/uploads/image/files/ketokuvofapubuwumuneroxip.pdfIn PDF document text
    • http://portalpr-b2b.es/img/user//file/_0023532001631709514.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/gozaxe.pdfIn PDF document text
    • http://sahrugs.com/userfiles/file/98335439962.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/29077824416.pdfIn PDF document text
    • https://cortopolis.ar/userfiles/file/tulepa.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/16140bc03df329---refilolinijuxopa.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/HTGXzuRVGb4/uplcv?utm_term=double+reverse+uno+cardPDF 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_off0000f3f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C07 18560 bytes
SHA-256: 0fc6e6828e47937179c06891844f8706a02613b8156e69990f2500437f27afe3
font_02_sfnt_off00013c11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C11 10480 bytes
SHA-256: 1cd7c9f47ec6842be8f663639ddb95a68af6426b8e86a8115a8cca563e1c5811