Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c6fdb2b11ff95c…

MALICIOUS

PDF

83.3 KB Created: 2021-09-04 10:51:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c70fe73b7950bb5da250120ce593c75d SHA-1: 584229ae59f38c4354605f01d8c9e0b3280990e0 SHA-256: 81c6fdb2b11ff95c1c442320c584089ce17d6db81473ec92650eda4d9c11b076
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to other PDF files hosted on various domains, many of which appear to be compromised. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics indicate a pattern of using link farms on disposable or compromised hosting for distribution. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery through these linked documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://wilocom.ro/ckfinder/userfiles/files/gumegonozobotawizu.pdf In PDF document text
    • https://moto-trend.cz/public/files/fck/file/felejawebazepuwaku.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/4b14f7d9765547774330797543645618/85087637296.pdfIn PDF document text
    • https://zold-kommando.hu/files/41279490289.pdfIn PDF document text
    • https://hankilfood.com/upfile/files/19234495333.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/sekipojute.pdfIn PDF document text
    • http://konstruktor33.ru/app/webroot/files/files/30588875368.pdfIn PDF document text
    • https://bodymason.com/user_uploads/files/lenutak.pdfIn PDF document text
    • http://suachuabaoduongmaynenkhi.com/img_quanganh/files/gixemufojokimolekure.pdfIn PDF document text
    • http://burragebrothers.org/demo/jolie/beta/userfiles/files/vagemu.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160bd9d9c6ea83---nubemelosanek.pdfIn PDF document text
    • https://appfacile.it/file/93707822305.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac3b7ba6df6---40102463596.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff1b331181---kafuxujozu.pdfIn PDF document text
    • http://centreforeffectivecoaching.com/media/file/34107056542.pdfIn PDF document text
    • http://mp-hd.de/data/aktualnosci_imgs/file/19323280148.pdfIn PDF document text
    • https://bravo-hk.com/userfiles/file/lewesudixedidujekonal.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/besiwe.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/mapolovif.pdfIn PDF document text
    • http://cuanhuaabshanquoc.vn/files/rutokeligulitegoxeroxidet.pdfIn PDF document text
    • https://www.lightingsolutionsal.com/wp-content/plugins/super-forms/uploads/php/files/a9883e5dd5c81f63dd56fa0dfff5ef8b/64470525800.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///rubiw.pdfIn PDF document text
    • http://bugaboo-buffalo.eu/UserFiles/File/dafosefuti.pdfIn PDF document text
    • https://envida-nieuws.nl/bsb_website/upload_fck/file/pigovotokulorozinapezu.pdfIn PDF document text
    • http://manavpublicschool.org/manav/userfiles/file/41732940489.pdfIn PDF document text
    • https://aeternoplanning.com/ckfinder/userfiles/files/73565959023.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=bagatelle+beethoven+pdfPDF 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_off0000e0bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f8d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D2 10676 bytes
SHA-256: 64f558ab34ce102c591688ec11d8fc7ac143789ad3ddc993247a83b00c5f4749
font_02_sfnt_off000110d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110D2 17924 bytes
SHA-256: 460782398118151b8647cabce1a5a8da117f646b1936b5340ffe5d58abba2b45