Malicious PDF — malware analysis report

Static analysis result for SHA-256 6938db5e850d4536…

MALICIOUS

PDF

67.8 KB Created: 2021-09-14 14:21:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: de970ddb27dc80b5aa3960a74df18397 SHA-1: 40309ea7c9c50fd84799a7211480e8a61701c739 SHA-256: 6938db5e850d45368f4f3278dc940add4f65041acca3e9304c138126b85de078
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery through these links. The document body is unreadable, but the heuristic firings clearly point to a link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://worldplastsolution.com/ckfinder/userfiles/files/tebuj.pdf In PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16138e49ebd536---guvuwatiroxomagituma.pdfIn PDF document text
    • http://uat2.hkha.com.hk/ckfinder/userfiles/files/13884092507.pdfIn PDF document text
    • http://snap-drone.com/userfiles/file/fexoxaxuge.pdfIn PDF document text
    • https://equalland.com/uploads/File/liginutexilexidiputejuja.pdfIn PDF document text
    • https://burstallconrad.com/editor_files/file/tememulixizupejosuzizuw.pdfIn PDF document text
    • https://nhuadailoan.vn/upload/userfiles/files/66769425426.pdfIn PDF document text
    • http://chinazzjx.com/d/files/gagife.pdfIn PDF document text
    • http://conhantaoankhanh.com/webroot/img/files/98154474947.pdfIn PDF document text
    • http://remobudostol.pl/pliki/81137621837.pdfIn PDF document text
    • https://pt2-turbo-j3t.com/contents/files/nikupepa.pdfIn PDF document text
    • http://verynailscm.com/user_img/file/fojom.pdfIn PDF document text
    • http://pk-rowery.pl/user_pict/file/774546875.pdfIn PDF document text
    • http://form4concrete.ru/pics/cont/file/34357074281.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/jobiso.pdfIn PDF document text
    • https://kolbandibileklik.com/resimler/files/18757451729.pdfIn PDF document text
    • https://inprovitecuador.com/ckfinder/userfiles/files/17930071121.pdfIn PDF document text
    • http://gazomotor.com/allinone/file/tuligevo.pdfIn PDF document text
    • http://chayka-svg.ru/files/44184390425.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16132f19534ae5---44644535142.pdfIn PDF document text
    • http://stapper.de/sites/default/files/userfilesfile/dizofogomakotaza.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137fe3c8c3d1---88711571285.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=io+mmo+gamesPDF 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_off0000ad72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD72 15192 bytes
SHA-256: 5fced5b5c6d9bcd5e2debd9beb5fb88842899c3aa58c228bf455b8785d9cca88
font_01_sfnt_off0000d3d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D7 9960 bytes
SHA-256: 8aa14a0abaa340fb8a26e908e4025bc504d65dcc1176648e03fed39e14f64e7f
font_02_sfnt_off0000e9f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1