Malicious PDF — malware analysis report

Static analysis result for SHA-256 33477228816f270b…

MALICIOUS

PDF

74.0 KB Created: 2021-06-10 11:53:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 5bf3f36db4c616683f3b401e14bd2793 SHA-1: e7a5233a569b683a117c96fa0385cd145d17f8c4 SHA-256: 33477228816f270ba0d30f8d8255409dea30146435b3e15af5f8645f36d7417e
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external resources, many hosted on compromised WordPress sites, suggesting it is part of a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution scheme, likely using a spearphishing attachment as the initial access vector.

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://laborke.ru/uplcv?utm_term=barron%2527s+gre+math+workbook+pdf PDF link annotation
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/cc08afa6ee7d0d3142064dca24e116e0/denudinunegu.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c03a15c2054---87410993635.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083616b71e0e---mulunivumajevu.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607472fc98be8---xalozapepa.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/e4a271589a3bc768dab7ad9608224c77/83091485387.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075da10b2937---wabirivodusesabalevafo.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160baccca01fdc---80647344236.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c2efc1813---29773469114.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae71ed719b---salasiza.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/bkm0jq7a601e9b36if3ra9m9b4/bazegidupoxe.pdfIn PDF document text
    • https://susta.vn/userfiles/file/vunivofinutopigelat.pdfIn PDF document text
    • http://mobilenmr.com/files/files/pefelufurepenojawewu.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d288508f73---lozitedorimoju.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a462ce57f0---pozew.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/6c0af13662e6780a72f67c60edd91a57/18082906936.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb7aca504b5---51446796458.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/84faffb746f75fc43e64e0c5f4aa4b05/perirofedafas.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c549ec275a---75867469383.pdfIn PDF document text
    • http://fanti-fitness.pl/uploads/assets/file/lunimexixakowiwolefojo.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_off0000d7a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A8 5800 bytes
SHA-256: d7b4a15844673f9f739e1debe01317760d0cd91ef14730867e192ea9cbfe5f74
font_01_sfnt_off0000eb58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB58 20580 bytes
SHA-256: b587a17fc3fb5d040961260c75b10837f364d9dc0c5634ed40d28167f1b565c7