Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef920da87344f9eb…

MALICIOUS

PDF

71.9 KB Created: 2021-09-26 14:03:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c77b137cec3456771ac00f3c0dffa0eb SHA-1: 546669520311d28e83181aacc5be6e895c8b7db7 SHA-256: ef920da87344f9eb75b04e9730a2dacbb775eaa3080e7c9b62499645fe468510
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it is part of a link farm designed to obscure the true destination. The embedded URLs point to various external PDF files, likely serving as a distribution mechanism for further payloads or phishing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1613f915e8a2bf---99707086591.pdf In PDF document text
    • http://idroter.org/userfiles/files/lasujavososelawemuwewuw.pdfIn PDF document text
    • http://tko.wavedev.net/img/files/files/sonelewo.pdfIn PDF document text
    • http://carrasvilla.es/uploads/files/94118118360.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/23cf36f557d59829e5612ae8c3dfb620/menezifojelal.pdfIn PDF document text
    • https://nazrabilisim.com/calisma2/files/uploads/wurewelamesimok.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1614b81d4ea8f3---43950852802.pdfIn PDF document text
    • http://www.mousumibanerjee.com/fckimages/file/faxavalunusumoxuz.pdfIn PDF document text
    • http://zekejozsef.eu/FCKfeltoltott/file/kajufozuvakisutuvewet.pdfIn PDF document text
    • https://ever-progress.com/upload/files/satalovinulekijedomegox.pdfIn PDF document text
    • https://transport.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/tiseweguxulukove.pdfIn PDF document text
    • http://emblem4home.com/UserFiles/Member/File/39041206771.pdfIn PDF document text
    • http://kbo.pl/ckfinder/userfiles/files/74266143366.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/44215068706.pdfIn PDF document text
    • http://chemtron-vostok.ru/media/file/96400631951.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__614C75F48E417.pdfIn PDF document text
    • http://abworder.com/uploads/files/wirabosatuvovoduzulezib.pdfIn PDF document text
    • http://www.prunay-en-yvelines.fr/ckfinder/userfiles/files/rijaneresosaxita.pdfIn PDF document text
    • https://marblobath.com/app/webroot/img/files/35309100487.pdfIn PDF document text
    • https://biserica-izvorul-tamaduirii.ro/files/8669854139.pdfIn PDF document text
    • http://dafangtour.com/fckeditor/userimages/file/39548382682.pdfIn PDF document text
    • https://cafesca.mx/ckfinder/userfiles/files/13310723545.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/mowoteg.pdfIn PDF document text
    • http://savemaxint.com/files/file/gerelowesa.pdfIn PDF document text
    • https://ku4ysk-9lgp4y.com/contents/files/mimifofafovaserafaso.pdfIn PDF document text
    • http://ptichile.cl/userfiles/file/45128546765.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=movieflix+hollywood+moviePDF 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_off0000b554.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB554 10348 bytes
SHA-256: 1d81fbbffebe4b765719cfa8720ab916d5439a9e39eabef1caaf020f36477437
font_01_sfnt_off0000ccaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCAF 17844 bytes
SHA-256: 160545df75f2fdc514a0768d324b67f11e0b24112fb760f9f03cb9b92592bac7
font_02_sfnt_off0000fa54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA54 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1