Malicious PDF — malware analysis report

Static analysis result for SHA-256 e22da7b45ac1a8d3…

MALICIOUS

PDF

75.6 KB Created: 2021-06-11 03:56:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 7f2e271bbe0457090ba07cdeedfe3ef0 SHA-1: fcb9f3d34e3913eace7a5b012b26f5a4f39628ad SHA-256: e22da7b45ac1a8d3dbf1224e76fde813dbac09fe3dfdd619c1d2be5e04fb9a3f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document employs SEO poisoning by masquerading as a free download for a calculus textbook to lure victims. It contains numerous links to compromised WordPress upload directories and disposable hosting, suggesting it is part of a link farm designed to distribute malicious payloads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the download and execution of further malware.

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://pixomot.ru/uplcv?utm_term=calculus+with+applications+11th+edition+pdf+free+download PDF link annotation
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/76ff0a49a5773a16ab7a504a37bd2ec1/31732052077.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160961778185fb---90068481670.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/ddb4c83891bcfbe0688619d8b9bdfc48/vufifukamiromagimo.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160a678fe9a9bc---4803177534.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606d60b2c9eee---14057701528.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/70c2ef4dbcbe8128d6fdb78105eda429/41921568199.pdfIn PDF document text
    • http://aeronautike.com/userfiles/file/55633885000.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/3f39e83da7b034c20b511a0bfb0a4be7/74323681726.pdfIn PDF document text
    • https://napraforgohotel.hu/upload/file/28850779219.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf95c03357---26882965006.pdfIn PDF document text
    • http://filatelianumismaticaumbra.it/userfiles/file/97480447038.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086a943d05f4---83834048930.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ef10081f5---83952077119.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/842010040acf8cddc100f0e50fab8f5b/kujujegojuridi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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_off0000e784.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE784 5292 bytes
SHA-256: d9156416eec1c0f695ec6bb96c62826045396138c8c75b75144b34122c47745b
font_01_sfnt_off0000f992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF992 12092 bytes
SHA-256: 00f1b970e97ba2f100b07136ef643cfdebc47974d29aa053a330f2e5b5e0ef06