Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c08e3c251c36fa…

MALICIOUS

PDF

80.0 KB Created: 2021-09-06 16:34:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e69d500478f66433081d57eeff88472f SHA-1: cd59d450fb7e3df24a1a416597cfca05ff386d29 SHA-256: 28c08e3c251c36fa6bf12fe060fb8779509c4fbe837af6ffec81ca2a3f999f8c
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier. It contains multiple heuristics indicating it is a link farm, with several URLs pointing to compromised WordPress sites and potentially disposable hosting. The document body is unreadable, but the heuristics strongly suggest a phishing or malware distribution attempt via malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609817f20f000---51454797873.pdf In PDF document text
    • https://aadharshilaschool.org/userfiles/file/91482503524.pdfIn PDF document text
    • http://novichiha.ru/pic/file/lukovegovokojibovezat.pdfIn PDF document text
    • http://nanoscopy.ru/uploads/files/rawenaluf.pdfIn PDF document text
    • https://toananhmedical.com/uploads/files/lapigalajiviwun.pdfIn PDF document text
    • http://unsersohn.ch/images/file/bakamotexeke.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/nujamolumibar.pdfIn PDF document text
    • http://navigator-nsk.ru/userfiles/file/jufewaxalopi.pdfIn PDF document text
    • https://ecoverservice.be/gallery/file/82513219482.pdfIn PDF document text
    • https://tonthephunglan.vn/upload/files/82888133316.pdfIn PDF document text
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/916695552.pdfIn PDF document text
    • https://mmszke.hu/files/file/64445703471.pdfIn PDF document text
    • http://bydnjl.com/userfiles/files/gemofedefizaz.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2339d79ce3ab18ad75b340490f4573f9/welegilejedevosof.pdfIn PDF document text
    • https://topupdana.com/contents//files/xosupaxagizedipolenutokin.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16077e7d64e553---46957435935.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/b0fda74308743974e727119786a96f0a/fexilijumogaremumipupurog.pdfIn PDF document text
    • http://stardentalcare.org/userfiles/file/70715666300.pdfIn PDF document text
    • http://dgxzz.com/uploadfile/file/karerotaminuz.pdfIn PDF document text
    • http://agavietnam.com/img/files/63624850726.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/43b62f0683ecb0096aca6bcc4e4779fe/kiragukizugexisuvutekabil.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/66289499758.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=bakteri+klebsiella+pneumoniae+pdfPDF 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_off0000d57c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD57C 11044 bytes
SHA-256: 845a5755da6647355d5e35d433dbaf143835d07717cec879c1adc370c484e20f
font_01_sfnt_off0000eefb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001070d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1070D 16904 bytes
SHA-256: 76ea90a18506ffa7659033a384cbbf5998ee2d20223743074599915113bd4775