Malicious PDF — malware analysis report

Static analysis result for SHA-256 66dea21ee88f20f2…

MALICIOUS

PDF

87.8 KB Created: 2021-07-03 03:09:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 480fc65ece27f4e3e4b6872d774f63f1 SHA-1: 84144ddc6f1bf8840357133340706afa34f1581e SHA-256: 66dea21ee88f20f2ef38250fcd8565a2e83f060acc49a9eb35550c801651a5fd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress sites and disposable hosting, suggesting it's designed to redirect users to malicious content. Although no scripts were extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://vo23.ru/upload/file/42043593709.pdf In PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/c5f8e95ba4c5f58c1219760012790f9e/69803879215.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/0b118c734ea288982efb7e442411b44c/44942894296.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a11ed758d---tedoxel.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/e5a9bcf01a76d99a166a753b6ed13083/gitom.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/d0ae4ecf14135dbb437f9457cb186a3f/29912186000.pdfIn PDF document text
    • https://cuisinescartier.ca/upload/editor/file/zefixevatukazikisif.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/f5ad6b798e27a10e55cd43cefb0e3b08/rekob.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7e4f760bee---36570718517.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dbd286cd23---rajinomukinaw.pdfIn PDF document text
    • http://scamps.biz/userfiles/file/18729274532.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/fenavinexelodeka.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1607d3094572ed---mokevulepipara.pdfIn PDF document text
    • http://ideviceplus.nl/app/webroot/files/userfiles/files/82867076571.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/75361174243.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608cfc446a390---gosibisosewavoj.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1c663c4f0---98299475904.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608f5bffe07eb---mufuwoxufowaropitiki.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/sii8q5h0i7psvng3piug6g0ee2/84702837641.pdfIn PDF document text
    • http://anapro.com/ckfinder/userfiles/files/92445589507.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/efb3ea3d71e5cd71e6668bf912729799/vokemizagixipuso.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/jogovorovogonoxeguma.pdfIn PDF document text
    • https://www.schroedersales.com/wp-content/plugins/super-forms/uploads/php/files/5f8a50c78492804da0a1c40c983df10a/81513349896.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607730dd54eb2---25985715515.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/73455955024.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=blue+and+green+streaks+hairPDF 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_off0000f647.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF647 16752 bytes
SHA-256: 1c82310e2dbbeb20987ea0759dc58a1c7dabc53303fefde162b1c3320191c1dd
font_01_sfnt_off000121dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000139f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139F3 10652 bytes
SHA-256: 5ad1cd2a525340099470772fccdeb425bf8625c1790726f605ad01b35f48766e