Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4a0b9a5b7e18d60…

MALICIOUS

PDF

72.1 KB Created: 2021-09-29 00:49:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 17c5c9dd93eab38a769f6dec3b7dd8c6 SHA-1: a72b513ccb69ee4d8cbbdd024238db876ebb42f4 SHA-256: d4a0b9a5b7e18d60d50052cc3eb9b5268f8329c38db8f70746a694d0994f085e
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded links, many of which point to external PDF files hosted on various domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates that the document is acting as a link farm on disposable hosting, suggesting a malicious intent to redirect users. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted, but the overall structure and link farm behavior point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 4

  • 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://cwpni.com/userData/ebizro_board/file/vubumurefibab.pdf In PDF document text
    • http://thesciencenetwork.org/uploads/files/kowokagujokagasadol.pdfIn PDF document text
    • http://111-orte.com/testarea/cwsCMSlight/media/files/wolerobobiworasemotige.pdfIn PDF document text
    • http://floridare.ru/app/webroot/img/uploads/file/550708_58082930361.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210923130050.pdfIn PDF document text
    • http://stellarp.com/userfiles/file/70941752002.pdfIn PDF document text
    • http://apcmagon.com/userfiles/90039463244.pdfIn PDF document text
    • http://jungam21.com/upfiles/file/1632863609.pdfIn PDF document text
    • http://jplus-ag.com/upload/files/BodyFile__6142CA3CB26FC.pdfIn PDF document text
    • http://smwiarus.pl/ckfinder/userfiles/files/10748373335.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-9/file/rijokolo.pdfIn PDF document text
    • https://kildevangen.dk/files/vuwazokigufukubitavuke.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/9385333749.pdfIn PDF document text
    • https://reha.bg/content/upload/file/kiriwipodavadew.pdfIn PDF document text
    • http://myoffice2561.sesao33.net/UserFiles/File/14940322282.pdfIn PDF document text
    • http://daglichtfilters.nl/ckfinder/userfiles/files/duzaxunibat.pdfIn PDF document text
    • http://kennycojewelry.com/userfiles/files/202109/1632367290.pdfIn PDF document text
    • https://vanphongphamhienluong.com/upload/files/63864175380.pdfIn PDF document text
    • https://rosanaalvarracin.com/userfiles/file/23174744431.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/foludago.pdfIn PDF document text
    • https://its-bulgaria.bg/files/file/68571462885.pdfIn PDF document text
    • http://breakevenpoint.pl/uploads/editor/file/lidanenobuzuw.pdfIn PDF document text
    • http://trivio.it/userfiles/files/jaweluresiwupusol.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/edeac9dc75047f04d0290bba56b1d98d/78976298798.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161515bf611893---56258855371.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=last+shelter+survival+mod+apk+downloadPDF 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_off0000b643.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB643 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE55 16820 bytes
SHA-256: 889c5da59606a8c5eb0034182251bf0b37b54c12da52e5cd58e733e72ae7691c
font_02_sfnt_off0000f8f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F7 10960 bytes
SHA-256: 738ff64152bbcea38abd25b50c0850a36d4418d8d66433f1997d6d8a148e63ea