Malicious PDF — malware analysis report

Static analysis result for SHA-256 53d8c73dc2108d1f…

MALICIOUS

PDF

70.2 KB Created: 2021-06-07 03:28:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 52946fea52fb99c3500558f86680c8c5 SHA-1: 7c9d3eb5f026d3a96cf3e2e4638c5ce5375fd7a3 SHA-256: 53d8c73dc2108d1ffb10a171d58c28ec10a23a101a1d036df96530b0e792c6b7
156 Risk Score

Malware Insights

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

This PDF document is identified as malicious by ML classifiers and ClamAV, detecting it as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories, suggesting it's part of a link farm designed to redirect users to malicious content. The document's apparent purpose is to trick users into visiting these sites under the guise of providing information on writing sponsorship proposal emails.

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://laborke.ru/uplcv?utm_term=how+to+write+a+sponsorship+proposal+email PDF link annotation
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a73c8962abc---ranavegubixugapixi.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160725485a6303---52962640245.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b05131afbc5---xorudepipoluripi.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/01e850d4686817ff7e99a05823b6d823/losodoxosawik.pdfIn PDF document text
    • http://nowyhotelik.pl/userfiles/file/52060519234.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/63538f0688f3d5458ce48edc84a21286/75612385666.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b0fcb7d8cd2---sutevatenununuronoxo.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1394ae092---65435882628.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/tqtkqicumjqpa6789n2m3iroic/95035061865.pdfIn PDF document text
    • http://chrislahoda.ca/userfiles/file/29080024528.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/s19dip27urn7f57li6cimbu360/misamavafagazuzovenela.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/27229bf85b8e9dea695ae99ed2acb5a0/xakununebunogibi.pdfIn PDF document text
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/1b8d2f3u2pkqgnfh41vj3qpbtv/javituvofasogubozuserur.pdfIn PDF document text
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc5ac198e1---28418746265.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160760f581ad57---71480178640.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_off0000d803.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD803 5112 bytes
SHA-256: 81f80c47e6766089792f7e894a9213e24f7a9abd4599f42bf5b0f17e0ad5b623
font_01_sfnt_off0000e949.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE949 10196 bytes
SHA-256: 0bdbfe06aeb31ba3e71cfb2f848f40734c79386c5262819be9eb952bd0774390