Malicious PDF — malware analysis report

Static analysis result for SHA-256 683d427f8d700e57…

MALICIOUS

PDF

68.4 KB Created: 2021-09-15 13:27:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d33289c68d5e977ec3bf3f9fc650bbf5 SHA-1: 6b2d8a1eb609e7a8491ee87b6df868b4b5661c27 SHA-256: 683d427f8d700e5792cc1ca5accd550384dc15f161f4ef9e64cfe7de198a02cd
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, so the primary attack vector appears to be the redirection to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

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://22vek-omsk.ru/fck_editor_files/files/gononuk.pdf In PDF document text
    • http://eggtesting.com/admin/uploads/file/sosakif.pdfIn PDF document text
    • http://soyaksiesta3.com/userfiles/file/83621905190.pdfIn PDF document text
    • https://economiadecomunion.com/ckfinder/userfiles/files/79055717653.pdfIn PDF document text
    • https://franciscojaviermoreno.com/DocsCKeditor/files/7850608571.pdfIn PDF document text
    • https://shoppingplanet.ro/ckfinder/userfiles/files/kosimimem.pdfIn PDF document text
    • http://sushrutproctology.org/ckfinder/userfiles/files/pedumabojinijogujim.pdfIn PDF document text
    • http://vakoplus.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/97798720237.pdfIn PDF document text
    • http://erimti.com/userfiles/file/88615390710.pdfIn PDF document text
    • http://parfumerieindex.nl/images/uploads/20253400421.pdfIn PDF document text
    • https://tekstilkentrehber.com/upload/ckfinder/files/pajil.pdfIn PDF document text
    • https://hashtag.school/userfiles/file/65342283503.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613406388a7b2---70424443757.pdfIn PDF document text
    • https://www.channeloflove.com/ckfinder/userfiles/files/91629548084.pdfIn PDF document text
    • http://mywayrtk.org/userfiles/file/49248056097.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/7301d9dcdaae5a3f2e25e6cc22274952/xudesomipigigususinir.pdfIn PDF document text
    • http://partnerplus30.ru/images/fornews/files/93801253295.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/buxelisatep.pdfIn PDF document text
    • https://everestart.com/images/stories/file/bobitem.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/959af065827ecaab51eb386e102ef109/14554336347.pdfIn PDF document text
    • http://webinaris.training/ckfinder/userfiles/publics/files/tifazijobusesugup.pdfIn PDF document text
    • http://lnaixi.com/userfiles/file/20210915160813_1039327561.pdfIn PDF document text
    • http://cauthangdep24h.com/upload/files/jurodabesedebunodupezebip.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=60+seconds+download+free+androidPDF 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_off0000ae66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE66 10652 bytes
SHA-256: 986e8972e831c3f1e3f5a11ac577f3b5b60e1a4283bdf47b3a7337b8583b125b
font_01_sfnt_off0000c6ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6EF 14420 bytes
SHA-256: 2161b9d40d849160bc57cf01c02b81136fe09ad281e1c342dc7380837ebba45c
font_02_sfnt_off0000ea83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA83 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1