Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc62a857538f9c9c…

MALICIOUS

PDF

80.1 KB Created: 2021-09-11 09:14:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: 20f7613ec5f2fceab468a0da8b245d68 SHA-1: ec1bbdaa3f9833bca737b0324e3a188098f70e23 SHA-256: bc62a857538f9c9c166944527a288d4f16bc6fa782b8afd51bf65903fdf5e57c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, and it contains numerous external URLs. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates that the PDF is a link farm hosted on disposable domains, suggesting a phishing or malware distribution attempt. While no scripts were explicitly extracted, the presence of external URIs and the link farm nature strongly suggest an intent to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://philabc.ru/uplcv?utm_term=android+direct+share+remove+contacts PDF link annotation
    • http://rockhouseschool.com/rockhouse/uploads/files/bedojosisogawa.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/zixum.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/10669625253.pdfIn PDF document text
    • https://kaktutzhit.by/uploads/files/zumopezuluzali.pdfIn PDF document text
    • https://stka.gr/ckfinder/userfiles/files/xotasonuxofixepefexowu.pdfIn PDF document text
    • http://ristoranteyuri2.com/userfiles/file/69230122531.pdfIn PDF document text
    • http://vina2002.com/uploads/files/26568556272.pdfIn PDF document text
    • https://digireg.it/upload/13741866181.pdfIn PDF document text
    • http://vetsnab32.ru/userfiles/file/wolulizudovurup.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/futimoxaweze.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/vedadugabexedo.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/niratitagumutafimetib.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/21707566109.pdfIn PDF document text
    • http://wernitznigg.at/files/52326011154.pdfIn PDF document text
    • http://archiw.bibliotekalesmierz.eu/img/upload/files/gugerimumepenutopo.pdfIn PDF document text
    • https://congnghieptauthuyvietnam.vn/upload/files/vedatixi.pdfIn PDF document text
    • https://togeltop.net/contents/files/6529278506.pdfIn PDF document text
    • http://jsdarvin.com/files/goxifex.pdfIn PDF document text
    • http://jump360.co/upload/files/20210911015820.pdfIn PDF document text
    • https://kiaavcilar.com/upload/ckfinder/files/dekiverazadava.pdfIn PDF document text
    • http://nhatrangpalace.vn/app/webroot/upload/files/wasuxetavis.pdfIn PDF document text
    • https://luminex.pl/upload/file/622519072.pdfIn PDF document text
    • http://falegnameriacastiglione.it/userfiles/files/55365944867.pdfIn PDF document text
    • http://detskaoptika.cz/ckfinder/userfiles/files/6160658503.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f32289e8fe---puxikagoxopefawezokizajit.pdfIn 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://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_off0000d5e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E1 10636 bytes
SHA-256: e9585a1eb162f24de1d68a1f5ef9171114ae8a7dfbf5010ac80a6b9816d2f062
font_01_sfnt_off0000ee0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE0E 16968 bytes
SHA-256: ec78eb91a3451993e06bb5fa4764dbb6562b0d4f0d10104bd0893cd35f8b072f
font_02_sfnt_off00011a2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1