Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8998459bb522288…

MALICIOUS

PDF

70.1 KB Created: 2021-10-03 15:35:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 7c460b68f3ffbd3ecd9d6dd8bea3ce9b SHA-1: a4b4783c51799dd98be9140e79369874dbce8a53 SHA-256: c8998459bb5222889ec9f0250711e0dc87e547b54a34be59d569e23a60056363
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with many pointing to domains associated with link farms and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The file's structure and URL distribution align with techniques used to obscure malicious destinations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/b236u9enlvluped138r0f32l90/73376066984.pdf In PDF document text
    • https://pointwebhost.com/calisma2/files/uploads/1369142708.pdfIn PDF document text
    • https://mimpishiodua.com/contents/files/8101047145.pdfIn PDF document text
    • https://anzhero-sudzhensk.verlauf-ekb.ru/admin/ckfinder/userfiles/files/46576860876.pdfIn PDF document text
    • https://www.gurkhasfinance.com.np/ckfinder/userfiles/files/rolom.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/91856096871.pdfIn PDF document text
    • https://globalcareerclub.com/FCKeditor/userfiles/file/nepevux.pdfIn PDF document text
    • http://1day2night.com/UserFiles/file/87112448547.pdfIn PDF document text
    • https://seeyounow.net/userfiles/file/63022090207.pdfIn PDF document text
    • http://sanalights.com/admin/admin/uploadfiles/file/628419780.pdfIn PDF document text
    • https://solturism.ro/images/file/34749860225.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/09/21/lurasil.pdfIn PDF document text
    • https://inprovitcaribe.com/ckfinder/userfiles/files/lopatukew.pdfIn PDF document text
    • https://agronlogistics.com/userfiles/files/tepupuwubujo.pdfIn PDF document text
    • https://securitydm.net/slicice/file/44001029464.pdfIn PDF document text
    • http://jts-electrical.co.uk/ckfinder/userfiles/files/80088585718.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/pixiponokowufililigo.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/6ac66250440f11483c599657bf4614c5/vixivem.pdfIn PDF document text
    • http://bojovesporty.cz/userfiles/file/rigigune.pdfIn PDF document text
    • http://chiangmai-clean.com/user_img/files/wasipolurubelazageradodin.pdfIn PDF document text
    • http://federicozucchettiarchitetto.eu/userfiles/files/rubinefiganan.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/26996288139.pdfIn PDF document text
    • https://27061010.com/uploads/files/202109210520216188.pdfIn PDF document text
    • http://goldsunjsc.com/upload/files/70752802823.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=the+meaning+of+regardlessPDF 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_off0000b05f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB05F 10668 bytes
SHA-256: 5f28c131f76dfe890039bbeaf1dcc42fd980850fcf357a1e4d1e798240aa5ced
font_01_sfnt_off0000c850.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC850 16532 bytes
SHA-256: 5a77635e13741a4b8328faafb416925106ec4c733c0fc192d2e8cecf68212e39
font_02_sfnt_off0000f2e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1