Malicious PDF — malware analysis report

Static analysis result for SHA-256 76d7fc7df0fa5737…

MALICIOUS

PDF

85.8 KB Created: 2021-09-16 17:54:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e3d96399f89d31662807f5bd217e3f86 SHA-1: 3172c16566e7b35186a9a226ff2e0194fe6b7aaf SHA-256: 76d7fc7df0fa573756ded51bfdaa12df5dbad51636cc1b6c2c9dfb6bc051bc37
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV and an ML classifier as malicious, with heuristics indicating it functions as a link farm. Multiple external URIs were extracted, pointing to various domains that likely host further malicious content or phishing pages. The presence of PDF_SEO_DISPOSABLE_LINK_FARM suggests a deliberate attempt to obscure the true destination or distribute malware through a network of seemingly unrelated sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://medvor.ru/uplcv?utm_term=best+writing+apps+android PDF link annotation
    • http://lev-steklo.ru/userfiles/file/xulidef.pdfIn PDF document text
    • http://motovelo-nmsk.ru/userfiles/file/danakiwulojewuvotu.pdfIn PDF document text
    • http://knauto.com/upload/file///zegomepadenazipix.pdfIn PDF document text
    • https://uzmanwebci.com/calisma2/files/uploads/835471664.pdfIn PDF document text
    • http://vinhthuan.com/upload/files/vameninikupixeso.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/nuwepuzo.pdfIn PDF document text
    • http://soc-in.com/data/media/files/xalupurog.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16137659f93f72---7083764399.pdfIn PDF document text
    • https://venus-forever.com/image/files/xotukavisavanuxobefopil.pdfIn PDF document text
    • https://qeyeoptical.com/ckeditor/ckfinder/userfiles/files/dididowekoditosodaj.pdfIn PDF document text
    • http://fpole.ru/sadm_files/5065912748.pdfIn PDF document text
    • http://www.coverseg.com/uploads/ckfinder/files/zivuvilumovugojuxemuxad.pdfIn PDF document text
    • https://nbcmedia.vn/ckfinder/userfiles/files/ruvepujexamibare.pdfIn PDF document text
    • http://santamariamikado.com/uploads/files/niwujepixomaxikuloga.pdfIn PDF document text
    • http://goldsunjsc.com/upload/files/78609943564.pdfIn PDF document text
    • http://scuderieverdina.it/scuderia/userfiles/file/28262307259.pdfIn PDF document text
    • http://dija.lv/public/userfiles/file/20765397406.pdfIn PDF document text
    • http://sarica.com.tr/ckfinder/userfiles/files/22781945208.pdfIn PDF document text
    • http://goodlife88.com/uploads/files/fowowijovodega.pdfIn PDF document text
    • https://aiwcecckolkata.org/FCKeditor/file/4498266705.pdfIn PDF document text
    • https://ambalatender.com/upload/files/loraxiwogivawazosisawu.pdfIn PDF document text
    • http://dailitara.lt/bites/uploads/file/wegebofopujudine.pdfIn PDF document text
    • http://grandinhr.eu/images/user/file/94092845110.pdfIn PDF document text
    • 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_off0000ec94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000104ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104AB 10660 bytes
SHA-256: 377458324488238542ab8cd93fd8ed1688d1c0063cb6ad7acea400cf2bd25ec5
font_02_sfnt_off00011d19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D19 17180 bytes
SHA-256: d5026e8b006eb8743398015552c7b4893cb9a0d8e6cd961b56089fb75932302f