Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c237101c2ffc6ab…

MALICIOUS

PDF

81.5 KB Created: 2021-09-17 18:08:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 23748d4b41c1e141f6b4b5af89530e75 SHA-1: 0481dd25a4db57262690e76a477a4c2e9e22da3f SHA-256: 3c237101c2ffc6ab0ef601460955881eb84cce5ced46ad424ec5c5e34499185d
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The file's structure as a link farm is a common tactic for distributing malicious content or redirecting users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://k-newsletter.com/ckupload/files/92285309170.pdf In PDF document text
    • https://posaonakosovu.com/ckfinder/userfiles/files/20112174714.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/066f7fbba5ba77b1c79a2a4aabed1f69/dapalekadefedefepumanog.pdfIn PDF document text
    • https://ladida.asia/sporlegen/administrator/imagetempfile/36807110578.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/gepepesepunob.pdfIn PDF document text
    • http://trivio.it/userfiles/files/98871510030.pdfIn PDF document text
    • http://yidaig.com/uploadfile/file/20210911011535.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/fivum.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139c5792d118---65946635556.pdfIn PDF document text
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/4785307121.pdfIn PDF document text
    • http://snabsz.ru/ckfinder/userfiles/files/19230162946.pdfIn PDF document text
    • https://polaria.cz/images/file/15183624.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/ba68dceeff3dadb665bc3eacf6847946/80650619183.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/wodufog.pdfIn PDF document text
    • http://snsi.jp/image/news_file/43381814377.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/jixujepaz.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/cf7432d1e6fd0a085764b331ecab365b/91695751577.pdfIn PDF document text
    • http://tarnava.eu/user_images/file/gojuferipovumoledudopuv.pdfIn PDF document text
    • http://snap-drone.com/userfiles/file/34244753713.pdfIn PDF document text
    • https://palezieux.com/ckfinder/userfiles/files/zitalupilimetidore.pdfIn PDF document text
    • http://gzsjlt.cn/userfiles/file/92894101821.pdfIn PDF document text
    • http://odnoklassniki-files.ru/images/uploads/files/19801614751.pdfIn PDF document text
    • https://www.kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/kojinoga.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=iphone+6s+bdPDF 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_off0000d7e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7E8 18992 bytes
SHA-256: 9aa448538cb27c0c80365714f465ea68a65fd806e2d8634b1efdcabab61fe23c
font_01_sfnt_off00010a0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A0C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012223.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12223 10252 bytes
SHA-256: 3b91e0b1178bbf2d7a99759a0f27df19535506728a6c262f8ad24f3ba79594cf