Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ec1117323e9e80d…

MALICIOUS

PDF

76.8 KB Created: 2021-09-10 04:07:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: d10133ce80b5afce7bc1c4e23ddbdcb8 SHA-1: d0511b6d3fce23230baa3da22ec0c4ace5271a28 SHA-256: 4ec1117323e9e80d852a1f8e02ee1780c0e13523af7ac718f49ab8aecf871d3b
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable hosting. These links are likely used to redirect users to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=contestants+of+indian+idol+2019 PDF link annotation
    • http://to-tuong.com/media/ckfinder/files/35243686998.pdfIn PDF document text
    • https://thuaphatlaihanoi.net/uploads/files/wumonewexegaxuluti.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613406eb4bac2---jususugarosinunubokizawa.pdfIn PDF document text
    • https://essuances.com/ckfinder/userfiles/files/gedikulu.pdfIn PDF document text
    • https://tempegaring.com/contents/files/ninosewo.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8ad2dac06---3138008725.pdfIn PDF document text
    • https://marugame.hk/editor_upload/file/fuvewukikuropitalawusenos.pdfIn PDF document text
    • https://longhoang.vn/upload/files/zuxudetilevudaxunukovu.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9c4311197---kaforegegurananelegi.pdfIn PDF document text
    • http://panhongbo.com/ckfinder/userfiles/site_eachfun_com/files/59019970369.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/67723427551.pdfIn PDF document text
    • http://teplo76.ru/uploads/file/lefetudepexizuxisinita.pdfIn PDF document text
    • http://synergienetwork.net/userfiles/file/52392468410.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/306009598e12110d42d7f830e1a05944/mibunomemibupofezajiru.pdfIn PDF document text
    • http://www.dkmodels.net/ckfinder/userfiles/files/tusefeminifibi.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/9m2ivltivp096ug9gqmtij91o2/52642516765.pdfIn PDF document text
    • https://perfectprojects.ro/userfiles/file/zowidegupazojuduronafeki.pdfIn PDF document text
    • http://laserbeautymachine.net/d/files/nomareboxiz.pdfIn PDF document text
    • https://ms2oke.com/contents/files/75326895732.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7df1a21b6---2317103221.pdfIn PDF document text
    • http://01host.ru/userfiles/files/sebinegizezelibib.pdfIn PDF document text
    • http://lednotice.com/userData/board/file/36483868878.pdfIn PDF document text
    • http://synphabase.ch/upload/file/79423347106.pdfIn PDF document text
    • http://greenld.com/userfiles/33585490369.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_off0000c55a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC55A 10740 bytes
SHA-256: 41e22ecfa061f619602527c0f5e5eaadbce3a6c4314a5468a1614b66e1dfc9c0
font_01_sfnt_off0000de50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f662.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF662 17960 bytes
SHA-256: 81bedac0d8390d1c76122fb391c870e4b846cf71e7772f64659e8b1fd8d33b68