Malicious PDF — malware analysis report

Static analysis result for SHA-256 5cc3ac31e2b42807…

MALICIOUS

PDF

84.6 KB Created: 2021-09-08 22:36:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1b4208f8149fb62aef8455290fa58ab6 SHA-1: f4ad065fc88dd4695494c8ca407628fdf87d6ae4 SHA-256: 5cc3ac31e2b4280768fb0ca94b27994456b590ee94691c83d2f51e97c867c9ea
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as a phishing trojan and ML classifiers indicated high maliciousness. It contains numerous embedded URLs pointing to various PDF files hosted on distinct domains, suggesting a link farm or SEO poisoning tactic. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically identifies this pattern, indicating the file's purpose is to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://pc580.cn/upload_fck/file/2021-9-1/20210901074407228708.pdf In PDF document text
    • https://xn----8sbcehyodmtf1czh.xn--p1ai/userfiles/file/senivo.pdfIn PDF document text
    • http://stfurnimart.com/file_media/file_image/file/mokiwisedufugu.pdfIn PDF document text
    • http://digitalpolicycouncil.com/imagenes/file/kexukivafefadodo.pdfIn PDF document text
    • http://birizgardenhotel.com/userfiles/file/21555830096.pdfIn PDF document text
    • http://lindseyderence.com/userfiles/files/mipodigemu.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/ckfinder/userfiles/files/4701562970.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/qkc8eg2tk94be8sea8e3799sut/3889828289.pdfIn PDF document text
    • https://aradmissions.com/ci/userfiles/files/56906393504.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/17180069479.pdfIn PDF document text
    • http://estatepie.com/files/userfiles/file/ligojoledufavomakixul.pdfIn PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/kipitiwo.pdfIn PDF document text
    • https://xn--72ca1bzcdf9cg5df4n5a8cei.com/userfiles/files/zisuramodixowodutatezitag.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/16103882576.pdfIn PDF document text
    • https://durimawar.com/contents/files/botit.pdfIn PDF document text
    • https://alirezamirmohammadi.com/images/upload/files/23651871326.pdfIn PDF document text
    • http://eatoceanic.iorderfoods.com/uploads/files/3321887025.pdfIn PDF document text
    • https://projekt-lesen.de/userfiles/file/ziruxunoba.pdfIn PDF document text
    • http://ricoconsultingattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/69751673843.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/4dpalr2dob881hqlhnaeq3ucik/12046619945.pdfIn PDF document text
    • https://stpm-sa.com/userfiles/file/fatajetutugav.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210904000702.pdfIn PDF document text
    • https://reviewz.eu/app/webroot/files/userfiles/files/namofulobawinaf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=bloons+td+5+ice+towerPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6BB 17900 bytes
SHA-256: a853eaf5216c049e95b10f5bd8f0dd69c71338ed18750a4a640b8743e2f44e79
font_01_sfnt_off00011577.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11577 10472 bytes
SHA-256: 2e2162d667bf63268d8a1dbac0d0b870e74caeb243513991f547ac8baf067d2c
font_02_sfnt_off00012d81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1