Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6623667cb8950cd…

MALICIOUS

PDF

81.7 KB Created: 2021-09-19 09:00:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fa4a383993ed961f85c253d00965ba53 SHA-1: bdda1d813a7dc920f403ce7bc99b37c5046e2a4a SHA-256: a6623667cb8950cde5d311849b6f8130e1d72afc4b7240fcaa374f68cb98ca2e
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating it contains malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document is designed to host a large number of links, likely for SEO manipulation or to distribute further malicious content. The embedded URLs point to various PDF files hosted on unknown domains, suggesting a link farm or distribution network.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://classoft.ro/userfiles/file/36946333474.pdf In PDF document text
    • https://tigapilar.com/upload/files/25429041609.pdfIn PDF document text
    • https://aparcaderoshaddaichile.cl/uploads/images/files/67592951115.pdfIn PDF document text
    • https://udruga-invalida.hr/files/ruduxodowezodebow.pdfIn PDF document text
    • http://knipia.com/userfiles/file/94951969572.pdfIn PDF document text
    • http://opuspointpartners.com/ckfinder/userfiles/files/60791615925.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/berapedofukodalapugo.pdfIn PDF document text
    • https://gimenezricarte-deltabogados.com/ckfinder/userfiles/files/sajewitowawegegonutativ.pdfIn PDF document text
    • http://oppedisanorobertosrl.com/userfiles/files/44364109176.pdfIn PDF document text
    • http://adice-area.com/pictures/files/88261314899.pdfIn PDF document text
    • http://gernano.eu/gfx/userfiles/files/75445775627.pdfIn PDF document text
    • http://growlink.biz/userfiles/file/gawidiw.pdfIn PDF document text
    • http://isagenixmakessense.com/ckfinder/userfiles/files/67988535155.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146c86c5457b---zibonigurazeliki.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/fabazuxaxarogikuparuja.pdfIn PDF document text
    • http://law885995.com/upload/fckimages/file/54520621363.pdfIn PDF document text
    • http://udokutscher.de/gfx/userfiles/files/famoxifero.pdfIn PDF document text
    • https://markmont.eu/editor_uploads/system/files/94171742730.pdfIn PDF document text
    • https://skvely-kup.cz/files/file/80495962235.pdfIn PDF document text
    • http://stoka-saarlouis.de/userfiles/file/76202614602.pdfIn PDF document text
    • http://www.solarwindependence.com/ckfinder/userfiles/files/pazukusuguz.pdfIn PDF document text
    • http://cssh.es/img/file/viguzazabonegabodu.pdfIn PDF document text
    • https://j26clean.com/upload/files/xisokagipipededar.pdfIn PDF document text
    • http://tianfonmm.com/d/files/xejizijexovenav.pdfIn PDF document text
    • http://swhos.com/upload/files/vixofuvejegexejuna.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=remote+control+android+camera+from+pcPDF 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_off0000dd25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD25 10660 bytes
SHA-256: cdb1e408c69ad7372b934b0b4bb33dd71423e0a246a212c7715fdd875042be93
font_01_sfnt_off0000f578.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF578 16648 bytes
SHA-256: 181c5d24cb80b57bbe788d1ed357faae7172063b90c32fdf8175b139e154af48
font_02_sfnt_off00012106.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12106 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1