Malicious PDF — malware analysis report

Static analysis result for SHA-256 b634b85daa6ecfef…

MALICIOUS

PDF

83.5 KB Created: 2021-09-01 01:17:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d7fd791b2db8b31ee9a235c7e7b366e7 SHA-1: 323e866c7db96a043df2d1fda5069e2387932730 SHA-256: b634b85daa6ecfef849d84c15e70db5f44d4fcdd78d48927055adcb542abba37
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, indicating a link farm or SEO poisoning attempt. The embedded URLs and the nature of the heuristics suggest the primary goal is to redirect users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 http://violetstudio.in/userfiles/file/legafovokijitorule.pdf In PDF document text
    • https://underworldgear.com/upload/users/files/losuwef.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160e2baea8a635---tedot.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606f09e97c534---62024731073.pdfIn PDF document text
    • http://batiment-tunisie.com/userfiles/file/vaxesuzikimu.pdfIn PDF document text
    • https://zionapostolicministries.org/uploads/file/72990757246.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/xagisulufudakaku.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/41492750646.pdfIn PDF document text
    • https://pointsourcegroup.com/wp-content/plugins/super-forms/uploads/php/files/fafd8eafcd4b363e90fd2fea093679ca/xivewugaw.pdfIn PDF document text
    • http://topas.lt/userfiles/file/52847311638.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-6/file/85078185719.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/2d52c85a68bca1cb4d9884f81824869d/sagejisufo.pdfIn PDF document text
    • http://70sromans.com/clients/871711/File/nisosoporupekekixo.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/25141955633.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160abead3c3ee4---82327157485.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c225641bc89---47520943680.pdfIn PDF document text
    • https://fourseasons.events/wp-content/plugins/super-forms/uploads/php/files/d3de03f5a38bd6dca894eac8e20642fb/marer.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/6a78c386917f6e2e3b1404c69bf40bcf/ribituxapaja.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b850bb07f57---74404996999.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/semibofibiki.pdfIn PDF document text
    • https://franchise-vietnam.com/app/webroot/img/files/14906897394.pdfIn PDF document text
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/877b04e18ade6ba3107a9a545806d903/1304236781.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075220ae7e9d---26364147891.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/sudesasezadilijuboxezux.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=lesson+plan+for+computer+science+for+b+ed+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_off0000de46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE46 10976 bytes
SHA-256: 5639757d8be09fddbd683b856a655256bc8c5b0f086e6710c83b112130dca76c
font_01_sfnt_off0000f781.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF781 18352 bytes
SHA-256: b961b6edb86eef111b43ef9e5bc8eb88f37ee929346b39ed29d7451140b93327
font_02_sfnt_off00012675.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12675 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1