Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3d3795f4b1d26b8…

MALICIOUS

PDF

85.0 KB Created: 2021-09-17 20:01:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b380b6298cc892f08a87df15b513666a SHA-1: 86ab8dc6284dff921c6c94f19da62e79ddfadfb7 SHA-256: a3d3795f4b1d26b8470d2484cf7b2e700f829709f23532c23a427f487ad640ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload storage, suggesting an attempt to distribute malicious content or phish users. No scripts were extracted, but the structure and URL patterns are consistent with a phishing lure delivered as a PDF attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://kabelkyaobuv.sk/editor_uploads/files/gesubunidotomojuze.pdf In PDF document text
    • http://jenan.com/ckfinder/userfiles/files/dafuwaxi.pdfIn PDF document text
    • http://cke.hk/userfiles/minezuvibilemi.pdfIn PDF document text
    • http://uralinteh.com/uploads/files/nokoralukunide.pdfIn PDF document text
    • http://mackielaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/koluvefovoz.pdfIn PDF document text
    • http://www.likoda.com.tw/upload/ckimg/files/nonenosefefep.pdfIn PDF document text
    • http://longruiglass.com/ckfinder/userfiles/files/20210910_050442.pdfIn PDF document text
    • http://midoriku.zaitakunet.jp/app/webroot/upload_images/files/mirelanizu.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/dbvbv9bdlmn28t8l1cchcsool1/1718481241.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/crblc670e5m052929i3dr4gd1g/zijezurozafivavokizigat.pdfIn PDF document text
    • http://staractivecollection.com/resimler/site/files/kepujibajo.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac88450a82---7722069694.pdfIn PDF document text
    • http://probeg2000.ru/files/userfiles/files/lomorelavujadoruduj.pdfIn PDF document text
    • http://essentielles-theater.de/UserFiles/File/6084000247.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/n014eqv5qpe4cqt019palmdmfp/monuxunuxijitaf.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/buxijogovebagase.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/25183352664.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/rodarolotuxujilaxixebudin.pdfIn PDF document text
    • http://vinhthuan.vn/upload/files/26606710395.pdfIn PDF document text
    • http://furnitura-syndicat.ru/ckeditor/ckfinder/core/connector/php/uploads/files/jurujabakatata.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/51609803662.pdfIn PDF document text
    • https://www.abandassociates.com/ckfinder/userfiles/files/buluvipidenorikeku.pdfIn PDF document text
    • http://parcroyale.hk/userfiles/kaseluxetuzuma.pdfIn PDF document text
    • http://riviera.az/userfiles/file/1281789669.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=1+racing+motoPDF 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_off0000e9bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9BF 10184 bytes
SHA-256: d5e49b810a9a0eccf787651c1e057df24aee608cdd1298f45ceb92dc2fa11597
font_01_sfnt_off00010089.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10089 17656 bytes
SHA-256: 20f23df1424aa8d07a8af611e2a6ce2439d88bac161b29e64bca425163885966
font_02_sfnt_off00012ec6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EC6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1