Malicious PDF — malware analysis report

Static analysis result for SHA-256 a79f372cadef4cfa…

MALICIOUS

PDF

74.6 KB Created: 2021-06-18 04:44:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 04f5b02d7e6d94cf768a52eb2ddd6336 SHA-1: 21da38acd1f8882a55fd484268d99f43e50c4dfe SHA-256: a79f372cadef4cfabeb1c16640c593a4d39208767ef4cf93359b4d48ce3e5ad6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains a link farm hosted on multiple disposable domains, identified by heuristics like PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM. These links likely lead to phishing pages or malware downloads. The ML classifier and ClamAV detection strongly indicate malicious intent.

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 http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608647c8bb24d---65337257516.pdf In PDF document text
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160839d21d1f29---57565485607.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/643cad67a7f0148b0b8e4e6dc52ba616/49449662985.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608395ba8583c---61989357537.pdfIn PDF document text
    • http://capital96.com/userfiles/file/kexep.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160758d170dd06---21964068977.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/44a98e3081923c4185eb423f223833b6/6996273245.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609b40c3de840---figudedikaxuwafalo.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/bb8dfaa6f1a7329cf6d9c5d565c40732/72098290188.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7fda30f0d6---98943011628.pdfIn PDF document text
    • http://cropscipublisher.com/files/upfiles/file/zobiviserulate.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/f9d18acc46792b3828db87a1815947b5/32785274758.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b18e53641a6---retova.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-5-3/20210503161259385520.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021043003175373499.pdfIn PDF document text
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3981cb2c14---kirudojazekegosulogo.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072391db8046---18738286924.pdfIn PDF document text
    • http://renovator.cz/files/file/vasopiwoni.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/~3/1KS0DP0cxss/uplcv?utm_term=intelligence+and+analyticsPDF 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE521 5048 bytes
SHA-256: 9da5e13d4154f78cf0957b70175ee5c37838837ce1554014150a162b3ccdb1d2
font_01_sfnt_off0000f66d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66D 11124 bytes
SHA-256: 5ce425313f608a77d4bc3b75ee244123a1b5fb1dc6c4907a6769de7e71d26224