Malicious PDF — malware analysis report

Static analysis result for SHA-256 28607f16dc064bcf…

MALICIOUS

PDF

102.9 KB Created: 2021-07-15 09:41:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: f276bd4aca234c818c9dc67c596a7a7f SHA-1: e5d6b21335352a64115c698f86c23fc157f1cde9 SHA-256: 28607f16dc064bcf0bb428f0ee5799b48feae5f6169627d101d9db460c96b8eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to multiple compromised WordPress sites, a common technique for distributing malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable binary data, suggesting the primary malicious function is achieved through external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9926

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://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160b35eb71390d---89233992446.pdf In PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/7186153893.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/9s5r72qe9m49jm9qns1n6jh9oc/kageliredepikitalukexow.pdfIn PDF document text
    • http://humboldthighclassof79.com/clients/1/19/19f040aad945c40a0acbd79abd3dc6cb/File/48329354104.pdfIn PDF document text
    • https://alternatifhirdavat.com/upload/ckfinder/files/wuwatategenarejoza.pdfIn PDF document text
    • https://dm288.com/slicice/file/sakidowagadatiw.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff63f6bda6---guliwifemibujamulumazam.pdfIn PDF document text
    • https://coastalstudio.com/images/main/file/89594516649.pdfIn PDF document text
    • http://doks-films.com/pcms/content/file/37480788249.pdfIn PDF document text
    • http://zonwering-belgie.com/ckfinder/userfiles/files/jugimeda.pdfIn PDF document text
    • https://globalazeri.az/wp-content/plugins/super-forms/uploads/php/files/psm0q4eopialoj582ab1npebe7/49332775803.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/30bcc2bd3719b587bd83b288ce5fb6a5/70069047424.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/a12mejiiiso7k69nl01ctpne3s/wevoluda.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607448d3a921f---58971055823.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/bv0fa04d4da1571n1r1ctn3otc/tewob.pdfIn PDF document text
    • http://www.aqsclimited.com/EditorImages/file/fixewagorewalufonivok.pdfIn PDF document text
    • https://securitydm.com/slicice/file/54867683582.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb84ab60d0---pijole.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a333d7507e8---61224569632.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/doboxogerogumofax.pdfIn PDF document text
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/dq7kg713t5nfoo1ugg1j04kod1/pufus.pdfIn PDF document text
    • http://longarmquiltacademy.net/fckeditor/userfiles/file/34418014447.pdfIn PDF document text
    • http://nextgenship.net/upload/file/20210614162364847561.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf9e0c0562---61593685719.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=what+does+projectile+protection+do+in+minecraftPDF 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_off00012d74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D74 17932 bytes
SHA-256: 0b38ee000b5b2c59a088c81acaac8b5ce3e85864703369904b27cdf1a336bdf3
font_01_sfnt_off00015ca9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15CA9 11008 bytes
SHA-256: a70c023185855f03793ee17d7c2aaea0673fefd03ad06e472bcbe8c585526a9c
font_02_sfnt_off00017601.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17601 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1