Malicious PDF — malware analysis report

Static analysis result for SHA-256 225d8523677bfb8b…

MALICIOUS

PDF

73.1 KB Created: 2021-06-09 23:34:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 0bbe925fa766c241037da41607ace7b9 SHA-1: a3821e66002627ec33ce2d4d2664be69b32f0fc7 SHA-256: 225d8523677bfb8bd8bd991ee58b9761f547e86d4ea0601251e956404a7a7443
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other domains, likely to redirect users to phishing or malware distribution pages. The document body is heavily obfuscated and contains what appears to be metadata from wkhtmltopdf, suggesting it was generated programmatically rather than being a user-authored document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://laborke.ru/uplcv?utm_term=watch+inuyasha+season+3+online PDF link annotation
    • https://bellevuecommunityfoodbank.org/wp-content/plugins/super-forms/uploads/php/files/5d34106accf3c008c431d1ff0f4446dd/roretagebeke.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea2c4b7f22---99290585266.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098adf1a297b---reguruxodezetufu.pdfIn PDF document text
    • http://beijingxinzhi.com/userfiles/file/20210510140124_2143186639.pdfIn PDF document text
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/88f3279913755e1d5e9c68c964b46e9f/ligutomakoxatodiputidup.pdfIn PDF document text
    • https://iominneapolis.com/wp-content/plugins/super-forms/uploads/php/files/20848d9746dab65492052b3878cd1f65/rijodofodetugupik.pdfIn PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/cd4b76df2a0503541198bf3bbe424d5f/97054140363.pdfIn PDF document text
    • http://littlepearlspublishing.in/data/eimages/file/satavorowajapamatutijan.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/dhqrd4j3q05472c2fk5v261rhl/8549561651.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160970667a59f5---fagewefagute.pdfIn PDF document text
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/9cbos60adrqtfgsirn3f7t483r/rozame.pdfIn PDF document text
    • http://www.odnpoznan.pl/fotki/file/file/21368246979.pdfIn PDF document text
    • http://webbuilders.com/files/file/60246995794.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/ruluruvagegab.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d638.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD638 3516 bytes
SHA-256: 4aec9304d7e7392b7187294bcf44b3812d83b4b8790663afbb5445579ec7691c
font_01_sfnt_off0000e2d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D2 5068 bytes
SHA-256: ca3917930418d2a35b23222c64ba9ef4c96eea5f68144f6ef9b23c363f6b2820
font_02_sfnt_off0000f424.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF424 10240 bytes
SHA-256: 14cf73f9e076f779582bf5aa79314e4a04a5166c2e5ebb1ed22e0340eb65307e