Malicious PDF — malware analysis report

Static analysis result for SHA-256 03cf081c2fb8a5f5…

MALICIOUS

PDF

84.1 KB Created: 2021-06-11 00:51:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 9c2374fa3106794bb3ee9ee574011ba4 SHA-1: 85f1755909c841e64898b3791c14cae455bb3711 SHA-256: 03cf081c2fb8a5f5899276f7bb4a723c6812b829356d97188bb791be29e0dd49
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which appear to be compromised CMS upload storage locations. The ML classifier and ClamAV heuristic strongly indicate maliciousness, specifically a phishing or trojan threat. The document body, though heavily obfuscated, contains references to 'cdr to psd online' and 'wkhtmltopdf', suggesting a lure to a fake conversion service that likely hosts 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://nomylo.ru/uplcv?utm_term=cdr+to+psd+online PDF link annotation
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b788e5132c1---67751052324.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b374bbd910b---91869087374.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/81609385282.pdfIn PDF document text
    • http://aawyx.com/sites/default/imageuser/file/tabiwugedufupatujemomabo.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/aoam8i43d61jahsehi7490j2t5/gepawajisizozopen.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a1335789d70---tofenanejafemo.pdfIn PDF document text
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/4ea769c6fa001681b858d98aeb4e9c45/falinoderorirogi.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/d5a73c79bed34a7939a05360ac6f1259/fofefanutebejogav.pdfIn PDF document text
    • http://metapolar.hu/tmp/puriwokewori.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/92d6bc4f62e5748fa0621c4a3d8eaae7/15415950617.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4b2d8da97---keditumobimalivotiz.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1607e986b92fee---24715082776.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b7b8cb91187---66446961329.pdfIn PDF document text
    • http://shsalumniauditorium.org/clients/f/fa/fa32e32112b7cad64a7d7e78b95ed61b/File/fixorasix.pdfIn PDF document text
    • http://casier-a-bouteilles.fr/file/xarozifewomufo.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/1l74gl2akt70psqvvgnlgu0mll/87877613893.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_off00010f21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F21 4648 bytes
SHA-256: 71d981da6072273bfca8b047828837b2b00c826c6c60d3211d6ab7e25a39464f
font_01_sfnt_off00011ef4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF4 11212 bytes
SHA-256: 264b52da1997a8f1bd91f03e803b11d6762a79cf3029800e9830f5cc373ca842