Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a156d6942410711…

MALICIOUS

PDF

75.0 KB Created: 2021-10-02 21:11:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9fc139f4ab1836d722677162e2f6d22a SHA-1: 1c0940e5dda2ed2d7b089b218b5f240d235bb65a SHA-256: 9a156d6942410711a177bac01c2c1a9d2af9d225bc9a9f5b88641d89549f9a4f
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to compromised websites and disposable domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm on disposable hosting. The primary purpose appears to be directing users to external sites, potentially for SEO spam or to serve as a stepping stone for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • 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=icc+cricket+world+cup+t20 PDF link annotation
    • http://bangdientunhk.com/upload/files/80631517381.pdfIn PDF document text
    • http://btfa.tw/upload/files/23513766107.pdfIn PDF document text
    • http://4seasonstours.in/userfiles/file/sevedogudijevomale.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/diwikuripi.pdfIn PDF document text
    • http://ngocvietbungalow.com/upload/files/lipisavijixepopapododefa.pdfIn PDF document text
    • http://mylodge-naoshima.com/images/blog/file/vabuzatefav.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16155ce7768e89---wemaxarugenewiruwer.pdfIn PDF document text
    • https://lideregitimpaketleri.com/calisma2/files/uploads/vadozuzapowu.pdfIn PDF document text
    • http://jan-fotografie.nl/upload/files/nupojanujilivid.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/5b155507261627a495f2759cc8b06b6f/zowelakujixod.pdfIn PDF document text
    • http://hawaiianhunareiki.it/file/figelin.pdfIn PDF document text
    • http://golfvillageonline.com/userfiles/file/94535107737.pdfIn PDF document text
    • http://dr-temt.ru/images/file/20370878688.pdfIn PDF document text
    • http://thestarbusan.com/FileData/ckfinder/files/20211001_61F4FB164DEA9878.pdfIn PDF document text
    • https://rrhh.fronteraliving.com/imagenes/contenidos/files/67046269164.pdfIn PDF document text
    • http://rjbmachinery.com/d/files/94241010920.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/5f6b7c0e3789006abb85cf4741ed192a/vofoduz.pdfIn PDF document text
    • https://heritagecambodiatravel.com/userfiles/file/tizibepumimofaragidide.pdfIn PDF document text
    • https://nstyapi.com/resimler/files/10229980188.pdfIn PDF document text
    • http://bajkolandia-leszno.pl/userfiles/file/dekikuguzum.pdfIn PDF document text
    • https://dfkcnc.shopper-store.net/file/files/mekipopiti.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/xabijujubosexivap.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_off0000bd3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD3D 18968 bytes
SHA-256: 64c4aade1d272cdead9e660b7c7104a674a571883997d60d6b56fdb0176489fa
font_01_sfnt_off0000eeab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEAB 10544 bytes
SHA-256: 94e2fe888e4c3abe7986962ad6c0816bb80b40c72f56f0d7efae170317aff6c2
font_02_sfnt_off000106e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1