Malicious PDF — malware analysis report

Static analysis result for SHA-256 c20b59eb5bfeedf1…

MALICIOUS

PDF

84.4 KB Created: 2021-06-21 18:13:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 364a8d5a286d4f09ce7ad6ad30764465 SHA-1: dd28412f1a6477a3e046002d3b8d16119e74a287 SHA-256: c20b59eb5bfeedf149ee2104877fc10d8e2fef68dc1bbf229cae1695c5a30615
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to potentially harmful content. The document body is heavily obfuscated and appears to be a byproduct of the wkhtmltopdf tool, offering no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/fe4ab5f2e5decb88d91a2a2219709cef/sefatemeref.pdf In PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/d4upnjo538951srdfnf379blk0/dobejuzotafigej.pdfIn PDF document text
    • http://matsonconstruction.net/userfiles/file/tusawajowevadelali.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/f45883675ba43c51b21257b99f5063f9/xobedimafamiperasum.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/36693055373.pdfIn PDF document text
    • http://jncs.kr/page_data/file/20210531034232.pdfIn PDF document text
    • http://kasargod.net/uploads/file/revepepawazapaxapijojizo.pdfIn PDF document text
    • http://box8websites.com/ckfinder/userfiles/files/sopufuxuxibetalazun.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202104/file/xotesurekabobepenad.pdfIn PDF document text
    • http://tgtech-auto.com/userfiles/file/63788003224.pdfIn PDF document text
    • http://wamer.org/userfiles/file/3785970716.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609bab80cfaaa---77960792981.pdfIn PDF document text
    • https://promise-land.com/upload/file/geroge.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160980d6fcd7eb---xopefobarorisi.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cba15dc7c94---17037575891.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/hopnj3h26pu1eahaunvelvvjc7/gusopiradubudo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=dorian+yates+blood+and+guts+routinePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001028e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1028E 5236 bytes
SHA-256: d45f6d53f985d94af330df002d2cf0bac135ab22bcbae43087d0bb67355c74a2
font_01_sfnt_off00011468.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11468 1800 bytes
SHA-256: 51ebeec29509b87aa858d500e37ac8853184703d07d1f913ce36d8e1dc7764c0
font_02_sfnt_off00011cf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CF6 11132 bytes
SHA-256: 09e0ffd302d0b7df088295b2c0be810d7aa39a4161e4947df14d3ed2e9f047b3