Malicious PDF — malware analysis report

Static analysis result for SHA-256 08631d4cf8453713…

MALICIOUS

PDF

84.4 KB Created: 2021-09-04 03:55:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1e850f5143a2ae9361a6d0dceec5fb1a SHA-1: 4a6b4d1d0d60d08129f984fd6937e22f8fa983e9 SHA-256: 08631d4cf8453713ffaee14d249fc0410749022def2b9d4d33c3a448c3edbc2a
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier. Heuristics indicate it functions as a link farm, with multiple embedded URLs pointing to external PDF files. Some of these URLs are hosted on domains associated with compromised CMS uploads or disposable hosting, suggesting a malicious intent to distribute further malicious content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://prokoncept.hu/admin/blogfck/image/file/jifimeb.pdf In PDF document text
    • http://yeosingol.com/FileData/ckfinder/files/20210803_C4BAA5EC60410FAD.pdfIn PDF document text
    • http://www.grupoaccs.net/ckfinder/userfiles/files/35338330520.pdfIn PDF document text
    • http://aygroupmuh.com/image/files/67808108376.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/55159806321.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/bosutarogiwuxivitozo.pdfIn PDF document text
    • https://webmenuplus.com/images/file/sumulugaza.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/39115798700.pdfIn PDF document text
    • http://mylodge-naoshima.com/gegijova.pdfIn PDF document text
    • http://magiccat.pro/ckfinder/userfiles/files/koxokowitudij.pdfIn PDF document text
    • https://aucordechasse.fr/vosImages/fowapi.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/5af367edadcc4aa30b66e054deedf472/10190184108.pdfIn PDF document text
    • http://ticaproduce.com/ckfinder/userfiles/files/kefij.pdfIn PDF document text
    • http://domholidays.com/userfiles/file/15626823512.pdfIn PDF document text
    • http://hccc252.ca/clients/e/e4/e484b38507f190a955b66748903449e1/File/katavevasenabidi.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/tijopukulovifotimatifuru.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/20qsclgurhkut35oqflu988m9r/89814374289.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/dalupipurutobiz.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079b5944f67e---rugevebuxewuwe.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aadf0580c73---wizaf.pdfIn PDF document text
    • http://silesiacapital.eu/data/file/ravulisofogotikuxet.pdfIn PDF document text
    • https://pfhotel.gr/ckfinder/userfiles/files/34098409549.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/defuzurirumumeketujimif.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/13991708319.pdfIn PDF document text
    • https://nergizleryapi.com/image/files/51623170291.pdfIn PDF document text
    • http://agro-vostok.ru/userfiles/file/84001260166.pdfIn PDF document text
    • http://ontsgoi.shop/uploads/files/xunenaxunuxope.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/0d6121e7b9897d0e1151e460b0204c9e/3339635686.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=governors+list+2018+pdfPDF 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_off0000e3c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fbd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBD8 18296 bytes
SHA-256: 0085bef04b0477de19a463dafe0739d1f9e26a41c8bc7c702cbc39752600f0c8
font_02_sfnt_off00012a41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A41 10936 bytes
SHA-256: ab7679b1fd400850ebb1b15100b4835085460db489f7238e2f731ca1fa5213ed