Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4915e1e16b9d83d…

MALICIOUS

PDF

87.1 KB Created: 2021-09-16 21:34:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fa77f49727bdac4852bb0d8afc3fb04d SHA-1: 9ab37c136299663d30afab0c2e34a05ad1f4108d SHA-256: d4915e1e16b9d83d64df0644aad2d40c0d0a92ea224f5b3eebdd92f488d32d9b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicative of a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of the document as a collection of links designed to appear legitimate.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://oniceh.ru/uplcv?utm_term=online+chess+game+for+ios+and+android
    • https://oglethorpeclub.org/~oglethor/UserFiles/file/84841788989.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16130a492d4fd5---28416222782.pdf
    • https://karolinanowak.com/userfiles/file/tunuwugutedavidokeju.pdf
    • https://hiddencliff.kr/FileData/ckfinder/files/20210913_FD6EE5A1AB38D842.pdf
    • http://whitedwarf.ru/public/images/ckfinder/files/zodegogajimiboxap.pdf
    • https://dpt-mh.com/uploads/news/files/59179700546.pdf
    • https://zagi.hr/files/38632351989.pdf
    • https://stealthwindow.tw/uploads/files/202109081702468273.pdf
    • https://www.barrau-philippe-sedeco.fr/ckfinder/userfiles/files/35109816996.pdf
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614066cbc4424---62921470516.pdf
    • https://autoroman-service.ro/imagini_ws/roniz.pdf
    • https://icbacademy.com/upload/files/38883023888.pdf
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/24834861646.pdf
    • https://haciendaloscipreses.cl/upload/file/5134618514.pdf
    • https://www.cifphosteleriayturismo.es/ckfinder/userfiles/files/79521407526.pdf
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7c9372dff---ruwazexowumavedurepezaso.pdf
    • http://vilocom.net/webroot/img/files/guzenametiditososuz.pdf
    • https://cicasoftavukatwebsitesi.demowebsiteleri.com/upload/files/67431059766.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138893741cb8---nijanof.pdf
    • http://www.shjkyq.com/up_files/FCK/file/72077699110.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613575dc90382---11061192488.pdf
    • https://pokereshop.cz/data/file/tofoneb.pdf
    • http://www.smartlandgroup.com/ckfinder/userfiles/files/40811566391.pdf
    • 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://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eefe.bin
071f1e296e7dd79b9f8691981c44f1556f8f364fa554a8e360eb84a3282815b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEFE 10848 bytes
font_01_sfnt_off0001079d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1079D 16792 bytes
font_02_sfnt_off00011faf.bin
fdce645dc120b6a328a71ff64cd74eddc6f48a4815ac3ee951f98b1501239444
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FAF 18024 bytes