Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9310a1e343b281e…

MALICIOUS

PDF

69.4 KB Created: 2021-06-12 11:09:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 9bbecdd01053db6fbd8f842b04c0df30 SHA-1: eeb8d1a7a39baaadbedb3a57b19e8f2e23eb8c2d SHA-256: b9310a1e343b281e2003285be2d1cd532caab0f83c36ada116831c9f8fdda836
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress sites, likely serving as a link farm to distribute malicious content or conduct phishing. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool sometimes used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://inwebjor.ru/uplcv?utm_term=can+you+make+a+pdf+into+a+link PDF link annotation
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab56ffe2ce4---41340008780.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160b797b76f3aa---nokeko.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609fd115b1af6---70035712351.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/gilekepefowobujomizikup.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6af431fc9d---rareb.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160823bf7adb49---ripelimar.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609703a841f65---lamex.pdfIn PDF document text
    • https://camgloberealtor.com/userfiles/file/27075454023.pdfIn PDF document text
    • http://petukmahaaaraj.com/userfiles/file/33266164839.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1607f3e9538fb9---51135449474.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608ff3f2b03f2---sebezixerufavola.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/c79bbc6a685f473cca1b2e659169272a/78047486270.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/d3b45959516ffde2a7fdd0a6624e57b0/46125682984.pdfIn PDF document text
    • https://www.tunnel.de/files/uploaded/file/68234848797.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/97840392302.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081725db5b7f---takin.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_off0000d583.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD583 4984 bytes
SHA-256: 1e1ff6e1826b454306fb1f9fec171ac7fc978e8c98d1dae5e78b26817d01ee85
font_01_sfnt_off0000e67d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE67D 10056 bytes
SHA-256: bd163299eea7e8486c440e81dd78f4f6116c3958daa9a833076a50a62b0230b1