Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8526c4f0274b229…

MALICIOUS

PDF

72.0 KB Created: 2021-06-18 02:36:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cb09308809751b0d257436955b0cdd39 SHA-1: 3b7b79333d51c0ea453718510be9a46af70abaf2 SHA-256: c8526c4f0274b2292ed5f249bbde7397a63fcec7e47935b0dca22f22ec4b77fa
164 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating it is a link farm hosted on compromised websites, designed to trick users into downloading files. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • 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://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/dnglp4rdmoml2n97e2dib1tp1l/tugezofoxinisufizedovif.pdf
    • http://studiobaldizzone.com/userfiles/files/sanabutujiduriw.pdf
    • http://agriturismolescuderie.eu/userfiles/files/49779716433.pdf
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/4d91e766ce25489a0bf171aa9955647e/28152260070.pdf
    • https://tedvandergulik.nl/userimages/file/getugamumodalubeb.pdf
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/730b93f6ef94888c3c36b9c83895352f/zukes.pdf
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8fe5b0444---9009775105.pdf
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609fe26517d5a---47600572164.pdf
    • https://roweryelectra.pl/app/webroot/uploads/file/16229252495174.pdf
    • http://55thocscompany.com/clients/62662/File/91971944818.pdf
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/f45823db5db8c2a99833508fe4042ae7/35401370812.pdf
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/fb1783e6fb6bb35bc29d57c2c379acb1/24266497433.pdf
    • http://anhuifan.com/upload_fck/file/2021-5-21/20210521092931645053.pdf
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/4f3a8c1abac7ac53cb76ae1d0cfdd53a/fomazobipovev.pdf
    • http://novichiha.ru/pic/file/bubimitevitoxakifelupafu.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/4jms8ioe18k576sjsm2nf1nmt0/pudujowefefavetevu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=pokemon+sword+and+shield+game+apk+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dda6.bin
876fd89a5a31d633a47c98cb7c25df93a947e53a6540a29649486b4478acf2f6
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA6 5528 bytes
font_01_sfnt_off0000f060.bin
95a59f87ba1e7c6494e0d66113b4a86d83775795e7e8a74be143f8d3e04f8c17
pdf-font-stream PDF embedded font (sfnt) at offset 0xF060 10924 bytes