Malicious PDF — malware analysis report

Static analysis result for SHA-256 28dccb7774ae57c8…

MALICIOUS

PDF

73.4 KB Created: 2021-09-08 07:36:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c2dd68efc5b366569b14301625f46289 SHA-1: 515c7aaf3e46136278b12efad4d0dcf5c7b6acc2 SHA-256: 28dccb7774ae57c8c5982567abad06fdee1b293fe1084de0de964069f47803d4
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised WordPress sites. These links likely serve to distribute further malicious content or lead users to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/16089f643cab16---turilanibeza.pdf In PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d87deb585aa---pavitenitizitafewamifu.pdfIn PDF document text
    • http://nissanotogovap.net/uploads/images/files/30408924494.pdfIn PDF document text
    • https://mayurherbal.com/userfiles/file/88920469221.pdfIn PDF document text
    • https://n-v-v.dk/userfiles/file/pololazawapadaludumosiwen.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3508ce78f2---tebufotazuwavediriget.pdfIn PDF document text
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/sm94gbe750vf48p9n5v22ils9l/polipularonezidotedesiw.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/b3atbe5ukc0n9mv9hidd98krbl/godonowobarik.pdfIn PDF document text
    • https://caror.hu/ckfinder/userfiles/files/57281985914.pdfIn PDF document text
    • http://podwierzba.eu/ckfinder/userfiles/files/sapufi.pdfIn PDF document text
    • https://audit-advisers.com/userfiles/file/6976450662.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/6c523cfa1dc936c259f11bbb7063e6c3/87078142958.pdfIn PDF document text
    • https://ecoledesgourmets.com/userfiles/file/kugevuzi.pdfIn PDF document text
    • http://takeacode.net/user/d41d8cd98f00b204e9800998ecf8427e/file/kuxifolepetufovofod.pdfIn PDF document text
    • http://firegallery.ru/img/upload/pijeziz.pdfIn PDF document text
    • http://mediacast.vn/ckeditor/upload/files/lexutatazi.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16098c6862c482---zosukuvolijozosu.pdfIn PDF document text
    • https://www.oalysa.cz/ckfinder/userfiles/files/19860826634.pdfIn PDF document text
    • https://wronba.pl/uploads/wysiwyg/file/78347745350.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160b5db204603d---58487172578.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/vijebegolugapil.pdfIn PDF document text
    • http://czytamzezrozumieniem.pl/userfiles/file/tatewokokitalumewuk.pdfIn PDF document text
    • https://rijst.nu/userfiles/file/wesawowoxumumopavo.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/dimaruve.pdfIn PDF document text
    • http://pincodehub.in/userfiles/file/96473668091.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=cambridge+history+of+japan+vol+1+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://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_off0000c3c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBDE 11476 bytes
SHA-256: 01949a83c1c706938be884a2a3228fa7c4ff693d5761f126fcc11a625f74af87
font_02_sfnt_off0000f66d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66D 15244 bytes
SHA-256: c13e48496ac574203a6916a0ba09b67fda636afe6270e6e03b263814d02618c4