Malicious PDF — malware analysis report

Static analysis result for SHA-256 90d91c7d9bc0a859…

MALICIOUS

PDF

87.0 KB Created: 2021-09-05 17:27:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a2085451faeafe1ba335582649fc70df SHA-1: 8e5878f9b61e2a41c8daad26fa5b4b4145245866 SHA-256: 90d91c7d9bc0a859afe0517404d28b2baebe3d77a2a76fc1b239bb7368c57b89
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these URLs and the overall structure strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://laborke.ru/uplcv?utm_term=chuy%E1%BB%83n+pdf+sang+word+kh%C3%B4ng+b%E1%BB%8B+l%E1%BB%97i+c%C3%B4ng+th%E1%BB%A9c+to%C3%A1n PDF link annotation
    • http://ankurgroups.com/userfiles/file/wovigunuwi.pdfIn PDF document text
    • http://rund.cz/UserFiles/File/megirawupafot.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096dcee72af3---90052170860.pdfIn PDF document text
    • https://devcons.org/uploads/userfiles/files/70465129372.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091ff4634030---xomeku.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/5cmlv60q09br2e37rrm91idfbs/nozawe.pdfIn PDF document text
    • http://fittbikese.hu/files/file/dokulutawule.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/10dngut79aknkjvcsbtnt5a9f6/72090244959.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/68973774951.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b5761f93692---zusazigagovisulil.pdfIn PDF document text
    • https://tahitotfaluovodak.hu/ckfinder/userfiles/files/62548184542.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160f71323c8682---95246034311.pdfIn PDF document text
    • http://mkngsp.ru/upload/files/nululuwag.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160928f1eb07ed---vudujumixen.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16088b95a2bd04---sitenegapuwuweba.pdfIn PDF document text
    • http://vietsinphar.com/uploads/files/65433350262.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/7558767099.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c8ce6daa378---92752973778.pdfIn PDF document text
    • http://khonggianxua.samdigroup.vn/app/webroot/upload/files/26178594940.pdfIn PDF document text
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/14b8f97132ea9f66ed23a7e36fbb3358/46091202935.pdfIn PDF document text
    • http://willismctyeire.com/clients/c/cd/cd1fd5262213d36872a77bd42df049b7/File/rikifejejomuxanajebemoza.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ab3372f5f8---2272807546.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160ba38b0bfdce---99580211094.pdfIn PDF document text
    • http://praconsulgroup.ru/pict/file/xulafubowoxanipe.pdfIn 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://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_off0000d797.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD797 31884 bytes
SHA-256: 4b8b9a3fe5f88a343d50ad4813a918b9832965bc98bd14e4b1ebc8a31af8662c
font_01_sfnt_off0001162b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1162B 12484 bytes
SHA-256: d1348bcd50c72e50cd08875709a1e52d8063cc609e5bb9b2b152d0827dbf8928
font_02_sfnt_off00013303.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13303 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1