Malicious PDF — malware analysis report

Static analysis result for SHA-256 153d78db846c2f40…

MALICIOUS

PDF

85.9 KB Created: 2021-08-24 20:12:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: b7726aa853c44bf384153b36ad818462 SHA-1: c6d912db893485602c321e507d9b4627537684a0 SHA-256: 153d78db846c2f4002680b35124b0f23c21664dec9dc2bf0a354cbd39fa7e29b
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting. The ML classifier strongly indicates maliciousness, and the structure suggests a link farm designed to manipulate search engine results or redirect users to malicious content. No scripts were extracted, but the primary attack pattern involves directing users to external, potentially harmful URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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://e-skala.pl/userfiles/file/sagusidobidapazu.pdf In PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/bdf84df4b8fed0297cab214d88a9e8bb/4124189115.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160980389ad78b---87345299624.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b640f095938---sukepudokez.pdfIn PDF document text
    • https://livres-d-art.com/ckfinder/userfiles/files/dukojavixisopekiga.pdfIn PDF document text
    • https://amblamy.ee/upload/file/nojexexesika.pdfIn PDF document text
    • https://morethancleaningservices.com/wp-content/plugins/super-forms/uploads/php/files/4e23bfa4646e2996330954c1955422c0/99104353940.pdfIn PDF document text
    • http://lottfamilyreunion.com/clients/878857/File/44078610653.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/528ba34f44f0c8072eb5b69aaba91c9c/fetumidove.pdfIn PDF document text
    • http://bhhangkhong.com/upload/images/files/69842088704.pdfIn PDF document text
    • http://gwhs79.com/clients/867100/File/fulinisabukuxepidaxamisos.pdfIn PDF document text
    • http://solar-makernavi.com/ckfinder/userfiles/files/1713083882.pdfIn PDF document text
    • http://dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/zitibotojuz.pdfIn PDF document text
    • http://aweibel.com/Photo/file/99344201012.pdfIn PDF document text
    • http://evolution-dev.com/file_media/file_image/file/laridexivaz.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e19eb81341---wiwelavoledimidibamara.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/1610d59144fa3d---pebimegedokoxameviv.pdfIn PDF document text
    • https://mobistore.co.nz/wp-content/plugins/super-forms/uploads/php/files/6a76a6a3ccdde04c2bcecba97c932505/wekepowuzofavun.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be7b802b6d3---luxabekojunogudivazejuf.pdfIn PDF document text
    • https://mariapolis.net/ckfinder/userfiles/files/voketopapusepo.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/593f9f7552aec7d1d144c1701829152b/8962689717.pdfIn PDF document text
    • https://adtw1.com/ckfinder/userfiles/files/73112433529.pdfIn PDF document text
    • https://hmanagement.net/userfiles/file/puvexozolejutokefivag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=best+way+to+attack+in+clash+of+clansPDF 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_off0000ec01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC01 17224 bytes
SHA-256: 0a3bcb9748d365953320af4dfa3f7b25e7e8c47cc4d63bf04e40e15e788c17bb
font_01_sfnt_off0001190d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1190D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013124.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13124 10676 bytes
SHA-256: 83c1d7af794e1a5fbb946e42ffd3b2fac49270445ac8a62ed619d947ddcc03dc