Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfea55abc0a950f3…

MALICIOUS

PDF

77.8 KB Created: 2021-05-07 18:32:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 4583d19b685ddc663a792530c8da6754 SHA-1: c2362e84b50edfe8529053f016b6e1b4bd4bf0c1 SHA-256: cfea55abc0a950f3a4eda9fa376c1471b13c175c2a5f6f4d4f1f5fe9fa496d70
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious sites. The document body, though heavily obfuscated, appears to contain metadata related to its creation, but no direct user-facing content that would explain its purpose beyond being a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16083a9c4cffd2---40351291366.pdf In PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/89uttd0fr50vvj9dpgdhu1rj03/towovipatoxixumizavize.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/89fe398f48a4da3e30cc9ec76b70c1b1/wodupifoterilolotorogunaw.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/ocdt71ld2i3n41crnflci7q6f6/tijotululiwoxunedij.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609489125a778---zatisipafinolajoduxiro.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/lewamitidesu.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/ff8977a9b1e6180af39da0ef488b3354/mogapogazifajegomamag.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083a247f1b86---kifapuliditenika.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf5d10fc04---nuzavexavijo.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/osugupofesasemalenipe.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086f60d25c87---49998216851.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085c80d74d7a---5750907615.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/2pfmjf9u55lbnvi4jl2bl7h9n5/32515034531.pdfIn PDF document text
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/nq0m9rbtkj9jl733004qosuls3/telibijosisegis.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/b44e0c27849d2947ecf892f8c5ea7939/jomunebukafilumev.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b440353451---31455023757.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=chain+rule+examples+with+answersPDF 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_off0000f05e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05E 5124 bytes
SHA-256: 602084bc78b8a704a7c66f685a2a4882203d2e56aecb301005144498c62ff66c
font_01_sfnt_off000101aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101AA 11744 bytes
SHA-256: a94ed96ae9ec81b22a7f8b8d6548b88f911e7efd47005d5dce17e76a1da46ecf