Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8a6f9197e2bec81…

MALICIOUS

PDF

96.1 KB Created: 2021-08-14 21:09:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ac5b6ba45d55e3426a056f71c9d4a6d4 SHA-1: 7189c1608378ce5b035e5a953cf86d3a75e9e2f9 SHA-256: f8a6f9197e2bec819f65e4b6a639975caa8828c4cf473be4a9cd4a786128f709
156 Risk Score

Malware Insights

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

The file is a PDF identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to potentially compromised WordPress upload storage and other domains. These links likely lead to further malicious content or phishing attempts, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/61735001883.pdf In PDF document text
    • http://goldmustang.com/files/files/rotelozevosopalas.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1623508358.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/ec012108ee1da0c34007c4eb1078caa2/nevegabusinipilegubinoso.pdfIn PDF document text
    • http://jplus-ag.com/upload/files/BodyFile__60E5170503803.pdfIn PDF document text
    • https://carlojans.com/cms/file/32897787906.pdfIn PDF document text
    • http://laros.cz/UserFiles/file/6790302267.pdfIn PDF document text
    • http://belhavenhighschoolalumni.com/clients/13962/File/zomomovejise.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-6-21/20210621044629798964.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606d16d49f0a6---40611589027.pdfIn PDF document text
    • http://remproekt-m.ru/admin/ckfinder/userfiles/files/nowivofepugiwexa.pdfIn PDF document text
    • https://olivier-daulte.com/ckfinder/userfiles/files/99753798027.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5d0edd9136---68122077004.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/ddc054bafa05f6dd8c926615f630b982/79892888758.pdfIn PDF document text
    • https://takarasushimn.com/userfiles/files/64086408082.pdfIn PDF document text
    • https://textosolutionslinguistiques.ca/upload/editor/file/kipixufipirixagawamevix.pdfIn PDF document text
    • http://vinhthuan.com/upload/files/77833659515.pdfIn PDF document text
    • http://officinedesign.it/userfiles/files/nabomatelag.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a305d3885f6---71151208169.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/xuliwav.pdfIn PDF document text
    • http://dgjst.com/upfile/file/61208823123.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610e08bac9a7b---fudopelawetuparedet.pdfIn PDF document text
    • https://xanbiente.de/userfiles/file/zurozekidejujesaxevorigam.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/ehc86gmkjhqovltdu3918sess0/leduxowino.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=the+end+of+the+affair+movie+1955+castPDF 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_off000114f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114F8 17036 bytes
SHA-256: a2c64ec1d70e4aaf684ba9ab14b38b905e198c3e32f390a00a0b1957368e0713
font_01_sfnt_off00014133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14133 11080 bytes
SHA-256: 85b64816c0f2e4159c9f0150974cf7d58a61299f3ec046bd2c454355881c9f72
font_02_sfnt_off00015aff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15AFF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1