Malicious PDF — malware analysis report

Static analysis result for SHA-256 a373f8673e2747a0…

MALICIOUS

PDF

69.4 KB Created: 2021-10-01 20:08:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 211efc366620c764ddb71048ccc5a2f6 SHA-1: 05173d2059a5a54ae972e8ecf37408d62008be34 SHA-256: a373f8673e2747a0b22a35b1ab12844649ca314f9168cdbd448e0da915ad52f7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a strong intent to lead users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://crewmak.ru/uplcv?utm_term=kotlin+button+onclicklistener
    • http://vatlieubaooncachnhiet.com/userfiles/file/23516919750.pdf
    • https://all-stage-meditation.tw/uploads/files/61386c4fc78d8.pdf
    • https://techinnsrl.com/writable/public/userfiles/file/lataduronisamil.pdf
    • https://www.idd.no/ckfinder/userfiles/files/pukinorofowitamapiw.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613671d2bc483---11899457125.pdf
    • http://luatsugiadinhviet.com/upload/ck/files/jerojumosuxol.pdf
    • http://assytekservizi.com/userfiles/files/35702316372.pdf
    • http://dongtienlamnghiep.com/upload/file/nexozisegesevu.pdf
    • http://demkapi.com/resimler/files/fupenur.pdf
    • http://slxiang.com/v15/Upload/file/20219201029354877.pdf
    • http://austral-immo.com/userfiles/files/jekubomuxadokugozifef.pdf
    • http://eastcoastbiker.de/sites/default/files/file/nufawanur.pdf
    • http://jmestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/muvipobobikejubemimo.pdf
    • http://vedepcuaem.com/luutru/files/goruxak.pdf
    • http://arcomproltd.com/userfiles/file/pibubefewalifasudaze.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613910b0b0d6b---53796703042.pdf
    • https://macroedunet.com/userfiles/file/23225767317.pdf
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/merasilezotinaxuwinokovaf.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/s5f3chuebodf8t8av5m3q5h355/giguvekekobup.pdf
    • http://samtekelektrik.com/files/nevixusifonul.pdf
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1613fb89fe9d6a---26209338334.pdf
    • http://swaminarayangm.org/userfiles/file/najojurijufepibasajosil.pdf
    • https://tpijobportal.com/ckeditor/ckfinder/userfiles/files/71134782800.pdf
    • http://cpk.by/ckfinder/userfiles/files/34395496881.pdf
    • https://eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/waledatizorutu.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b0f1.bin
4bd4b2d240d65b8b36740100583999f58bc2aa2de8df98c8ceb764ba242537a1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB0F1 10384 bytes
font_01_sfnt_off0000c897.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC897 16792 bytes
font_02_sfnt_off0000e0a9.bin
d402b47f1b7791d78d56aca544621724cdac17e56e970e2dfb6d142f7d9d64f2
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0A9 15564 bytes