Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c19ac77a07df207…

MALICIOUS

PDF

72.6 KB Created: 2021-06-11 21:32:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: a70ef2d5bd5dc0d9a03cfda3ed396065 SHA-1: 19cef2348a6451d7bff82ce3df8a36ae8102758b SHA-256: 3c19ac77a07df207260f2dcdf6556e0963f8c44db0c099c5ae1c2f68131339a4
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, directing users to numerous external URLs, some of which host further PDF files. The ML classifier also strongly indicated maliciousness. The primary attack pattern involves luring users to potentially malicious content via these links.

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://krisoc.ru/uplcv?utm_term=ielts+general+writing+task+1+examples+band+9 PDF link annotation
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/878d08f042a8a880ea977c65394924d8/zetuva.pdfIn PDF document text
    • http://cnhhgj.com/upfiles/userfiles/file/nuvutolosutifo.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607e4d85798fb---soturaxa.pdfIn PDF document text
    • https://www.treehousecare.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607f7d26e5170---66525058257.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/jvacv0ek6ntfkte947p4nefcms/fexagej.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/4c0453e7a6adee101730222be45d3f69/91939845300.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607869ee2f750---47926519503.pdfIn PDF document text
    • http://haiphongcontest.com/images/files/wixolujamatujilosapofesu.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/42579349732.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a490403aea5---83768141687.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/bfd21a9570ae1241799d320e6718ce51/bovufudazonepodubarujet.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1609c2815a82bf---7309769807.pdfIn PDF document text
    • http://faxik.ru/ckfinder/userfiles/files/gomeroxidekozaxikifidu.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609af62d62d03---vifipelumu.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/sa3km7fq3cnivn0hfeetbpt9nc/pekixogawuriropomawolap.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/4bc880ecd57c73207e7a668ca334f877/xutejukikijofaxej.pdfIn PDF document text
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7fe72f029---80475278851.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/7uannstkng2h8uf9av6cr2j4of/36169313855.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_off0000ddd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDD6 5788 bytes
SHA-256: 85a80f8f8715feb5dafbe8e538d42e64f4ecd9cd11258442a8b16ec35cf574b7
font_01_sfnt_off0000f187.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF187 10580 bytes
SHA-256: c83f58a5442600c6b04afd2462caa2aa9a2872874f2c9958e35a75bea2851614

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