Malicious PDF — malware analysis report

Static analysis result for SHA-256 548dd1530cee856c…

MALICIOUS

PDF

77.7 KB Created: 2021-06-11 02:00:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 1bb7176fc0db71f07735d64f217507d1 SHA-1: a8044874478c272688d6f57613f2afa123dfdd0d SHA-256: 548dd1530cee856c33a0936b012675a940d690a4c017bd299991d1c71407aae7
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of a "free stresser" lure in the document body, combined with the high ML classifier score and ClamAV detection, strongly indicates a phishing or malware distribution campaign. No scripts were extracted, but the embedded URLs are the primary indicators of compromise.

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://catamma.ru/uplcv?utm_term=free+stresser+2021 PDF link annotation
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/16099de80b7ed7---22385506790.pdfIn PDF document text
    • https://www.temsilcifirsatlari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160791c3835cd1---77691566344.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/n54vi39bnr3f42lm9emkk7vfv3/88276497604.pdfIn PDF document text
    • http://midiabyz.com/wp-content/plugins/super-forms/uploads/php/files/0535a8be4a764a86900a3f059d4c1b12/92351143999.pdfIn PDF document text
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/h01lrojq5hjt5k1nvpni00ccqn/wobowekudetiriwatowikib.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab92b2ecc05---fuzerosiritakaxamapebop.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16097aa1d5bf6f---15166925846.pdfIn PDF document text
    • http://extracam.es/app/webroot/arxius/file/nusazotesowisonapitazewez.pdfIn PDF document text
    • http://splogservice.ru/content/file/jowom.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b91cf283bc2---24291170637.pdfIn PDF document text
    • http://busanpc1.com/upload/fckeditor/file/12329675224.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16093d2ad2c7f4---rinopuxulixonobete.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe9845859a---mugubesibebogidavuvube.pdfIn PDF document text
    • https://biocoils.com/img/file/26115400941.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/b1af3839cb3db384ee5fd6def0cd9ed5/88883715196.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_off0000f552.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF552 4716 bytes
SHA-256: 7b70a3dfa34003d26b22e5d5826aea06eac2746b38f44217be94340931f0fa73
font_01_sfnt_off0001056f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1056F 10804 bytes
SHA-256: 80a029de9f16e318067d2897363b0613bba3b4326dca39db1f5143e7f751af1d