Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6635bfb4e758505…

MALICIOUS

PDF

110.9 KB Created: 2021-07-21 17:17:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 70c73754b0095d8a3f8af36509744d01 SHA-1: d053fee12581163613fc2988486cbfa70fca5673 SHA-256: a6635bfb4e7585053e39d97404df4fd5349b6fd893cce2ff7e2cf29d4bbe34a1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous links pointing to external websites, some hosted on compromised CMS uploads and disposable domains. The primary purpose appears to be redirecting users to potentially malicious content, aligning with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9887

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://billedbutikken.dk/articlefiles/file/42044154834.pdf In PDF document text
    • http://esipro.lu/userfiles/file/lurox.pdfIn PDF document text
    • http://bjeclinic.com/ckfinder/userfiles/files/mozobipilagokemope.pdfIn PDF document text
    • https://ilc.ua/wp-content/plugins/super-forms/uploads/php/files/bco84mn3am5j1f310dakn68ss1/35012495022.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/3rl3hc0ig6g63el10nfe1sam3h/15784448987.pdfIn PDF document text
    • http://avanti-kuhni.ru/upload/files/kavirenexomanu.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608618b006372---liwanukibinapozepi.pdfIn PDF document text
    • https://textolinguisticsolutions.com/upload/editor/file/91260359806.pdfIn PDF document text
    • http://mobydick-band.de/fckdata/file/60960963659.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/eaab28eec46fd67d6688b5c92389bf21/33846710767.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/4392dde3a20b47ae35bbf23aeebab0dd/95478238559.pdfIn PDF document text
    • http://murphysbeads.com/clients/54316/File/8743259866.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/1609887779dc9f---diluvub.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/5276ac06e91bba13935a82ce8e0010a8/kizaxiluvatezuxoxakeb.pdfIn PDF document text
    • http://xlsferrosilicon.com/d/files/xokilop.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16076005b926cd---24709489933.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/69036114775.pdfIn PDF document text
    • https://manualismedicina.hu/fileok/file/webugigoz.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfaa375e9dc---xevogaxupuworalar.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1608d6c4e89b51---tufuzopamiruni.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/37d54eaf8db5d75aa66eb20c8c98e8dd/xudesapik.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adcd5a32d80---32854640934.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/c0be3674c4e2e7c5054be2b451e06c90/vutemujunus.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/6f67e100e9a1afe565896123063aa01b/zujol.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9176e798c---fonipuv.pdfIn PDF document text
    • https://congtydaihai.com/upload/files/rusadubita.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/ae36d4deef93e999998d47e0ccd315ac/xifovajiwupojabenitunafos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=signs+you+are+neuroticPDF 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_off00014d5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D5A 10648 bytes
SHA-256: ee59b654e3d5ab6ba9dee58edb955978339d7ef734802772da5f569d2a485842
font_01_sfnt_off000165f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x165F2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00017e04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17E04 18068 bytes
SHA-256: e9198b5bb027590753446da92d9208dfaa625eb38bafdf615ae6882d41bdede4