Malicious PDF — malware analysis report

Static analysis result for SHA-256 c851bdc76c5e9b7b…

MALICIOUS

PDF

71.7 KB Created: 2021-09-25 06:36:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 24d59f8575c7fade139e4a1883ba5195 SHA-1: cdccc9a51b40e87f50ec5ab4ae2248a4a272e0ba SHA-256: c851bdc76c5e9b7b6a333e3a0f6de2b1d84e3222418e514def752aed3174877d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external URIs and is flagged as a link farm on disposable hosting, suggesting a malicious intent to manipulate search engine results or redirect users to harmful sites. The ML classifier and ClamAV detection strongly indicate maliciousness. While no scripts were explicitly extracted, the PDF structure and URI patterns are consistent with phishing or SEO-based malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://catamma.ru/uplcv?utm_term=gta+v+android+full+game PDF link annotation
    • http://gsprojekt.eu/userfiles/files/rizijebog.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/kovomidadixemovisatajosow.pdfIn PDF document text
    • http://villaelen.it/userfiles/files/kafudok.pdfIn PDF document text
    • https://ohcsi.com/ckfinder/userfiles/files/xisow.pdfIn PDF document text
    • http://sun-tes.ru/files/file/5615665113.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc1769bfd7---jigozujo.pdfIn PDF document text
    • http://asfalon.com/__files/file/34695169985.pdfIn PDF document text
    • http://rc-modeller.se/images/file///14017983168.pdfIn PDF document text
    • http://www.huescalamagiaenfotos.com/userfiles/files/gederinowexogibobo.pdfIn PDF document text
    • http://unseretochter.com/images/file/13639343329.pdfIn PDF document text
    • http://topbuild.net/content/xuploadimages/file/powezelemupubalovejozos.pdfIn PDF document text
    • http://weilandvloeren.nl/fckimages/51049965456.pdfIn PDF document text
    • https://www.nstoplana.rs/ckfinder/userfiles/files/nedamekam.pdfIn PDF document text
    • http://ohana1bbq.com/uploads/files/nalebejogixefojaxod.pdfIn PDF document text
    • https://dveropolis.ru/upload_picture/63881216258.pdfIn PDF document text
    • http://dalieuht.com/app/webroot/uploads/files/gaxedamago.pdfIn PDF document text
    • http://nobody-films.com/bpms/includes/fckeditor_uploads/userfiles/file/99346085260.pdfIn PDF document text
    • https://alubiasdetolosa.com/files/galeria/files/42998480877.pdfIn PDF document text
    • http://neboskreb-irk.ru/uploads/userfiles/files/21033477264.pdfIn PDF document text
    • http://shiny-baby.com/fileimage/file/2581705681.pdfIn PDF document text
    • http://orikon.net/Images_upload/files/sogulimoteserutepiwow.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/e3552394f6c489e3ac0afa368b763a4e/87187757676.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/golepidafozezisirusugo.pdfIn PDF document text
    • https://quanticabtl.com/cms_2018_quantica/sgi_userfiles/userfiles/files/5850070647.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/digufu.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/77441129286.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_off0000b5ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5AD 10732 bytes
SHA-256: 3b0fa8fad96ffe3b70bccfe02cd251ef5475f038ad26d5e6e43b2ad0515568c6
font_01_sfnt_off0000ce26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE26 16916 bytes
SHA-256: 06c1e58671187ab097791a63cbfeb8488c58befea3098dc4c80e30cecbc415eb
font_02_sfnt_off0000f901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF901 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1