Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ef4c5cddf21cc1d…

MALICIOUS

PDF

79.1 KB Created: 2021-06-23 23:26:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: c556c65b9693153e0c58f679d760e54d SHA-1: 1e9fd740ffdfa841130e9b40027a121eb52692ef SHA-256: 8ef4c5cddf21cc1dca309dc9974c2bc82faf4afc945686c60f106e60461acacf
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://aksukartela.com/images_upload/files/95260378475.pdf In PDF document text
    • http://musorcentrum.hu/files/article/file/nozukozibozaguxoxiwizo.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/529b9be60270d2e2d04ee3cb8b19a9ec/79920715351.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/fd76vrgctnjv4jn8t27euju41i/wibozavomisav.pdfIn PDF document text
    • http://sewakendragroup.com/userfiles/file/29822962115.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/77956a15ad80a4d1bb347d0b07d6f48d/pipikaziso.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/a4l1eutalhp27ln9t0p74tiia3/toxajexufubomi.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/77f1af32e85cc521053e68c4c30a6b21/41183830902.pdfIn PDF document text
    • http://onlineexpert.in/userfiles/file/95204536973.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c445773529d---86596585143.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaa0c1566f3---wapubuloxevolozir.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/sndao42ko6lg5jp2ggdpq3bu55/35190803425.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/fifovejukubafisanuviwelig.pdfIn PDF document text
    • http://naplesredeals.com/userfiles/files/kokilalorenididarukofi.pdfIn PDF document text
    • http://alituncer.com/userfiles/file/vozijonolajasij.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093d5459496d---68452962235.pdfIn PDF document text
    • https://advik.net/userfiles/file/42319179097.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=torrent+downloader+for+mac+catalinaPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f9f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9F3 5032 bytes
SHA-256: 0f3e474577953abc770a51a22d0fa006a9b1f84d288a70084dbe2c82faf3f4b9
font_01_sfnt_off00010b0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B0C 10680 bytes
SHA-256: 27f402790bc7199d6421478940d42d724c7713649a6ed7cd2a0af2f34404a80d