Malicious PDF — malware analysis report

Static analysis result for SHA-256 a456fb520a2665a4…

MALICIOUS

PDF

84.8 KB Created: 2021-09-14 11:17:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ba362708ce751480c30fd46db99d90e1 SHA-1: d4f56e3fb5784cd79364f48a8bf4114d5cf2e934 SHA-256: a456fb520a2665a47028e111f381064d628b7e619c708ba64eb8a47792994859
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV and an ML classifier as malicious, specifically as a phishing trojan. It contains numerous external URIs and is structured as a link farm, with many distinct hosts and links pointing to PDF files, suggesting a phishing or malware distribution campaign. The presence of embedded URLs and the overall structure indicate an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://infrive.ru/uplcv?utm_term=i+have+done+synonym PDF link annotation
    • http://hotelbasantresidency.com/uploads/debobax.pdfIn PDF document text
    • https://jogamiskolc.hu/ckfinder/userfiles/files/gidufidu.pdfIn PDF document text
    • http://redondoclassicburger.com/uploads/files/soliterelofisomapunavede.pdfIn PDF document text
    • http://pileki.com/imgup/file/bakefomimogovozolusete.pdfIn PDF document text
    • http://arrhythmiaclinic.com/userfiles/file/20210902220242.pdfIn PDF document text
    • http://djk-winkel.de/images/uploads/file/57655506544.pdfIn PDF document text
    • http://paitoonbox.com/userfiles/files/5640130007.pdfIn PDF document text
    • http://wpscrm.in/uploaded_files/userfiles/files/58915798659.pdfIn PDF document text
    • http://e-park.es/img/uploads/files/35052116927.pdfIn PDF document text
    • http://oticonshop.com/ckfinder/userfiles/files/dawosunom.pdfIn PDF document text
    • http://twtipa.com/upfile/files/2021/09/04/lisojutu.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/menokipomulevikodifevete.pdfIn PDF document text
    • http://www.como-grup.ro/fisiere/file/vugixujuk.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/78eaf2fb8467531f12c989eb36ad2b1a/fajuruwanujo.pdfIn PDF document text
    • https://martensmgt.com/business_school/uploads/file/gibuzidigog.pdfIn PDF document text
    • http://qlinairnv.be/userfiles/file/60770174860.pdfIn PDF document text
    • https://aucordechasse.fr/vosImages/30897181782.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4666c8e5a---vegesegovel.pdfIn PDF document text
    • http://brickform.cz/obrazky/files/ludazuge.pdfIn PDF document text
    • https://gentrilieu.vn/userfiles/file/larudinaran.pdfIn PDF document text
    • https://quangcaowebsitecomvn.xemlaco.com/uploads/files/32673011648.pdfIn PDF document text
    • http://www.pro9apps.com/app/webroot/files/uploadimagesfile/36563421194.pdfIn PDF document text
    • http://studioguidobarbieri.it/userfiles/files/43277728125.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_off0000e510.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE510 19644 bytes
SHA-256: 3530e275e3859a2fed8174f6510b945a4d5b5809960b55e8bbcb2814ff11ddbb
font_01_sfnt_off000116ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116EF 10308 bytes
SHA-256: a5b8fbfa86ab0d25dad4e0a115f5925c32f27220e9ebd92c1b24b73d7347dd15
font_02_sfnt_off00012dfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1