Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d131f2fb2e8ec3f…

MALICIOUS

PDF

95.3 KB Created: 2021-06-13 04:35:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 167c697d82f8c89085a30ea23e4262bb SHA-1: f8523be4e80b42ac918cbfe5380fbd31c39cb468 SHA-256: 8d131f2fb2e8ec3f2531fd9f9114a35beb2949839a5ba8ac182ec280e60e872a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV heuristic strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the nature of the URLs and the PDF structure points towards an attempt to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://chcial.ru/uplcv?utm_term=wii+zelda+skyward+sword+walkthrough PDF link annotation
    • http://lideparts.com/userfiles/file/1621297430.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609f47c267b22---87564250202.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c0ae76444eb---39631736896.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/nubogigiduxogerel.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/gmk9gnrmeeiefie4hns9jnrvc6/1479473299.pdfIn PDF document text
    • http://bukharajohnscreek.com/sites/default/files/file/pobapidefej.pdfIn PDF document text
    • https://nhachoxebus.com/upload/fck/file/lajebosejagatujulefe.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf18fb691d---vomisefavov.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/18520292436.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/9tg0dgc534ip85j3i9j0t9qs96/gizemisimamoladotenamezam.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607df589239c8---vikajula.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160825a480010d---mojapafukonepizejoxigel.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/hokgs7j10mco78gmi1gn2r1p0j/43712273471.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160a638ffe7ee1---87842862498.pdfIn PDF document text
    • http://alliusie.com/userfiles/file/85171690161.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b34afb4a9c0---92644223090.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011f33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F33 5672 bytes
SHA-256: c5924c37c78aae37d940d59992205b7315158f767c12c96588a508e9eced4254
font_01_sfnt_off000132e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132E2 5408 bytes
SHA-256: 149f11028eac0aaa7fa22cbf100a62cbf95740c312c8f1af299aad35a25a195f
font_02_sfnt_off00014567.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14567 12940 bytes
SHA-256: bbf9f7fda9a56b1b736d403244c3cd3fa10fe18b3093da0637be5369efca7c0a