Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8215864540f79ef…

MALICIOUS

PDF

82.7 KB Created: 2021-09-16 08:36:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 987d6425457f9a3557d13b886fe55570 SHA-1: 12a5802e1c242aa9b2c46dfbe2fbbe2e85ce1ccf SHA-256: f8215864540f79ef9acaa02917e47f055584995c7dd03480c43318fd5d413c6e
126 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to disposable domains, and is flagged as a link farm. This suggests the primary purpose is to redirect users to a network of sites, likely for SEO poisoning or to serve further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://kemxoi.vn/app/webroot/files/images/pages/files/bexivopabawumanovages.pdf In PDF document text
    • https://gogift-it.com/userfiles/files/pukipoxokerebuwis.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/tajenarolevuj.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/kokotorirokufurikonu.pdfIn PDF document text
    • https://vienhung.com/webroot/img/files/54208007123.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/16134989a179d1---musuxijekekonajonirafama.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/doguje.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/94436664959.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/63463646177.pdfIn PDF document text
    • https://oferta.lt/i/File/76898572331.pdfIn PDF document text
    • http://caogenzhiben.com/filespath/files/20210912142250.pdfIn PDF document text
    • https://mosallaesf.ir/uploads/ck/files/laloninewatumegev.pdfIn PDF document text
    • http://12shio5.com/contents/files/16832704930.pdfIn PDF document text
    • http://www.greenfield-sustainability.com/images/files/762073138.pdfIn PDF document text
    • http://xn--80adic7alej3d.xn--p1ai/userfiles/file/feremonenase.pdfIn PDF document text
    • http://ageddfjtjgrade.pretty-match.com/upload/files/71889971416.pdfIn PDF document text
    • http://nenorm.com/files/files/50357540182.pdfIn PDF document text
    • http://drukarnia-warszawa.pl/pliki/file/91775642925.pdfIn PDF document text
    • http://prestizhstroycompany.ru/SITE/files/editor/file/81960309863.pdfIn PDF document text
    • https://eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/93938088386.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/93525163232.pdfIn PDF document text
    • http://ttc-investco.com/img/files/tixozowijezew.pdfIn PDF document text
    • http://korea-seals.com/ckfinder/userfiles/files/biwozejew.pdfIn PDF document text
    • http://expertsystemgroup.com/file_media/file_image/file/nefuzipipa.pdfIn PDF document text
    • http://miyozenemeryville.com/uploads/files/budidapilez.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/66091166006.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=english+comprehension+pdfPDF 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_off0000dfd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD4 17388 bytes
SHA-256: 0b6449126557202e6cae23e2dc3a26ba714fd5ffe5af6319d9fbd8d3769c9df5
font_01_sfnt_off00010c9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C9C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000124b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124B3 10788 bytes
SHA-256: b5a29a8f63084e0e18bfb244ee1c5992e8b76ec7dc1c83781c3cf4c13c9cb9ba