Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bc1fdde86885292…

MALICIOUS

PDF

72.5 KB Created: 2021-09-11 06:52:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 61e068274ee0c6f53aebc0ed19505a60 SHA-1: 3bcf3a7c3df0c586f14be7aded53f4be4c0afc73 SHA-256: 5bc1fdde86885292a68409aac82335d8127c7aeaeabb9a376e0d5f8f877e51b3
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the structure and URL patterns suggest an attempt to lead users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 https://nomylo.ru/uplcv?utm_term=mow+zombie+mod PDF link annotation
    • http://thaisomboonautopart.com/userfiles/files/rasizimiraxunolikudafo.pdfIn PDF document text
    • http://udelimpa.es/ckfinder/userfiles/files/dibizafib.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/040146125835.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/8ba25e25ed6c32c0d9b6cffddff40dec/42909553267.pdfIn PDF document text
    • https://krzczonowice.pl/gfx/file/23393611978.pdfIn PDF document text
    • https://hahapediatric.com/uploads/files/202109090301156413.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613312e5105df---80047147969.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/doditemomogaboxil.pdfIn PDF document text
    • https://luminex.pl/upload/file/fizidozowafowesemon.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109081119185214.pdfIn PDF document text
    • http://bushurov.ru/images/files/fegakibixule.pdfIn PDF document text
    • http://boldino-hotel.com/ckfinder/userfiles/files/12589907103.pdfIn PDF document text
    • http://ferrogep99.hu/static/media/file/lusunujunifekezekabeje.pdfIn PDF document text
    • http://studiolegaletrotta.eu/userfiles/files/96538653714.pdfIn PDF document text
    • http://www.moyekolodin.com/files/xebumobigewapupewiz.pdfIn PDF document text
    • http://kolkandkolkdesign.com/site/data/ws/files/xazudageroxisun.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/h28jj7k7rb12sjvkbbfgt6i170/1517737767.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/c8b33iri572lu0gsnvf4p5lim3/nadopomujabakefebenipevit.pdfIn PDF document text
    • https://elesud.it/img_pagine/file/posibiwovusuferajudonija.pdfIn PDF document text
    • http://thietbimaugiao.vn/Images_upload/files/63958032170.pdfIn PDF document text
    • http://beveragesgs.com/userfiles/file/panidosoxinonaguzonig.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_off0000bb21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB21 17280 bytes
SHA-256: 700b283223e9111872d3583e69e81368d4c6b183f835fecabdba36039ffab649
font_01_sfnt_off0000e6dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6DD 10008 bytes
SHA-256: 0c0139815d60afadc644efc2a30ede9c75cca75d20ce40ecee5795372ab4ab1b
font_02_sfnt_off0000fd26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1