Malicious PDF — malware analysis report

Static analysis result for SHA-256 51df23f221ffaebd…

MALICIOUS

PDF

75.6 KB Created: 2021-09-17 12:37:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 2c4b09a4d2bba9f8c3c3b09211131124 SHA-1: 7f929f71aedb7f17fa861fd61a902d2b94b70ffe SHA-256: 51df23f221ffaebd0956fe4fec92c63d9a82a18a9c25cceccc2bab476c9215ea
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to compromised websites, many of which are hosted on disposable domains or use link farms. These URLs are likely used to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://chcial.ru/uplcv?utm_term=billiard+ball+model+by+john+dalton PDF link annotation
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16133c22255061---patogobifuk.pdfIn PDF document text
    • http://chamaeleon-produktion.cz/www/files/file/56631905696.pdfIn PDF document text
    • http://a9188.com/upload_files/art_files/files/20210910_150445.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/a53426a612ea7ccec59d84b9d927dbab/zizujuwuloxajagizolituzuv.pdfIn PDF document text
    • https://wtmasonry.com/ckfinder/userfiles/files/93574692818.pdfIn PDF document text
    • https://rm-parketi.si/uploads/nexisovoperasowolorutogo.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16140f5648a0a9---19310180622.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/51466155964.pdfIn PDF document text
    • http://agriturismolionsfarm.it/userfiles/files/koxolaxijigoma.pdfIn PDF document text
    • https://jimsdelibrookhaven.com/demo/jimsdeli/admin/userfilesfile/60344500242.pdfIn PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/56254587162.pdfIn PDF document text
    • https://proxus.nl/file/95037428142.pdfIn PDF document text
    • http://berbun.com/user_img/file/tutajatozozisekaru.pdfIn PDF document text
    • https://sweetburden.com/upload/users/files/13369522313.pdfIn PDF document text
    • https://sowlindia.com/userfiles/file/59840701009.pdfIn PDF document text
    • http://trineckevzdelavani.cz/webpagebuilder/ckfinder/userfiles/files/43073686546.pdfIn PDF document text
    • https://cryptoshift.be/anaeter_capital/siteadmin/userfiles/files/14025529112.pdfIn PDF document text
    • http://beachfirebrands.com/userfiles/file/dixumulod.pdfIn PDF document text
    • http://macro-e.com/app/webroot/userfiles/files/vuteno.pdfIn PDF document text
    • http://studioassociatoemc.com/userfiles/files/mokewarididifukazu.pdfIn PDF document text
    • http://rotarytattoomachine.co/project-new/christianbook/upload_images/file/35976986692.pdfIn PDF document text
    • http://cartonwrappingmachine.com/userfiles/file/98516195432.pdfIn PDF document text
    • http://bretagne.annuaire-regional.com/ckfinder/userfiles/files/25118148761.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/tavowuwumezedijem.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_off0000c312.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC312 16876 bytes
SHA-256: c0f61b23fd88f6f8cc933fc69858b5968b853323b3a063e311d83db6b47e9b82
font_01_sfnt_off0000ee66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE66 10780 bytes
SHA-256: bf6dfcb9fea9fee54191d18ad7b88e5e0f7d084b8587c68fd927e042139323f4
font_02_sfnt_off000106f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1