Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fef4db24edf5fa4…

MALICIOUS

PDF

74.0 KB Created: 2021-08-30 09:07:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8176b92c2cb1a1376e7a5d34003aa824 SHA-1: 56374aaac46399e8bfaefad3e196d1abfe7682fc SHA-256: 3fef4db24edf5fa48b141d024b62e0d3a8933a790313469e2fd6ecaca1c8e7ed
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm for SEO poisoning or phishing. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple distinct hosts and the use of 'utm_term' parameters in some URLs further support the hypothesis of a campaign to drive traffic to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://fashionflutters.com/ckfinder/userfiles/files/84961920730.pdf In PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f01f05d4ab7---vifokiliwuxa.pdfIn PDF document text
    • https://aokman-drive.com/d/files/pagokirulewonibeligovugim.pdfIn PDF document text
    • http://fincasotilloviejo.es/files/sotillo/_repo/file/vixenokakanepufi.pdfIn PDF document text
    • https://go2germany.ru/files/file/kalewegum.pdfIn PDF document text
    • https://cebubigsellers.com/userfiles/file/tebomilimebelat.pdfIn PDF document text
    • http://araonline.hu/uploads/file/42410458375.pdfIn PDF document text
    • https://www.stjohnhomelessshelter.org/wp-content/plugins/super-forms/uploads/php/files/65973e1dcdfbd4960b65bbad55f64957/40379194912.pdfIn PDF document text
    • https://nyirfa.hu/uploads/files/dofigixuxefikozuroxuxex.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1606d225d09cc8---nufunivepivonowixigopiti.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/73573931442.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/hko9f1rb3u6oqklevb2gtfpvcc/53733229124.pdfIn PDF document text
    • http://dichvugiayphep.biz/upload/ck/files/tanuwokemevol.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/6lpv2hijfsdnja2kt1m6bjdt83/35993102663.pdfIn PDF document text
    • http://ukkies.be/userfiles/file/lorinixadinav.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/d44f772a71982a614a3740a5e20d4c0f/99133094876.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/16075ba875e0ed---94897818130.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d5f6368e1b2---dadavanuzokojinagitur.pdfIn PDF document text
    • http://englandmatchshirts.com/assets/file/94247700186.pdfIn PDF document text
    • http://energyexcess.com/userfiles/file/40724520603.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/477055aa53939a28f11946aad0c48dd3/vufolaxujepagib.pdfIn PDF document text
    • http://ksklinika.ru/ckfinder/userfiles/files/wenagasogaziberet.pdfIn PDF document text
    • http://hoilhpnqbthanh.com/upload/file/kasofibefifawigod.pdfIn PDF document text
    • https://islandsvefir.is/wp-content/plugins/super-forms/uploads/php/files/fuj2aki3ajpuifvevu3l7dtj6i/27093216443.pdfIn PDF document text
    • http://1mosref.ru/ckfinder/userfiles/files/xutalirexogarasedop.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1611467cde2b4f---xobodiwul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=hollow+knight+white+palace+walkthroughPDF 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_off0000c164.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC164 15260 bytes
SHA-256: f2d7b5d99ef7ca36a1d7c5a55dfcd9e9c8c75637884c8b8715dec95c4e4d9d09
font_01_sfnt_off0000e7b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B1 10756 bytes
SHA-256: e21a9adb9af313950ce11dbd893c529398af9cac121e36f5a9bd62d2fe501fd4
font_02_sfnt_off00010069.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10069 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1