Malicious PDF — malware analysis report

Static analysis result for SHA-256 f288658d51b5528d…

MALICIOUS

PDF

74.5 KB Created: 2021-09-11 17:33:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9ff9b533b2e95bc162e2fda454dfb037 SHA-1: 1891a727299881af98d01c820841d01e19ed13e7 SHA-256: f288658d51b5528d6cc1a2f00262cf4939fc0ece2a41b52d5a1bb4b333b82f61
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a ML classifier and ClamAV, indicating malicious intent. It contains numerous embedded URLs pointing to potentially malicious domains, suggesting it acts as a lure to phishing or malware distribution sites. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a link farm on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://cructi.ru/uplcv?utm_term=principles+of+cell+biology+george+plopper+pdf PDF link annotation
    • http://csc025.com/userfiles/file/20210902102341_hp8x4i.pdfIn PDF document text
    • http://biogenetec.tw/image/files/20210904_043542.pdfIn PDF document text
    • https://oreopay58.com/ckfinder/userfiles/files/sojelodawubupusutuliw.pdfIn PDF document text
    • https://nirkongrp.com/ckfinder/userfiles/files/87502337792.pdfIn PDF document text
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/sanukiniv.pdfIn PDF document text
    • https://gitedu.in/ckfinder/userfiles/files/bajuvusam.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/64455900670.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16138599f670f9---77580059321.pdfIn PDF document text
    • http://torgoborud.org/images/file/1251129486.pdfIn PDF document text
    • http://alotercuman.com/ckfinder/userfiles/files/kabugifazajudagoviko.pdfIn PDF document text
    • https://senesi-sklad.cz/userfiles/file/musadukibagagozul.pdfIn PDF document text
    • http://amicissiapiemonteisa.it/userfiles/files/58517295071.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161322736e7b53---75138395140.pdfIn PDF document text
    • http://studiopol.com/userfiles/files/69808034664.pdfIn PDF document text
    • https://akemi.ro/hirek/file/48174917051.pdfIn PDF document text
    • https://tradingphrases.com/userfiles/files/lavomulaxovogojutase.pdfIn PDF document text
    • http://emusicmarket.com/upfile/board/files/93222981805.pdfIn PDF document text
    • http://esenkardeslerinsaat.com/resimlerfiles/80321767822.pdfIn PDF document text
    • http://vit-physio.de/file/87635703213.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/nasoletidebuterokabu.pdfIn PDF document text
    • https://medtek.vn/storage/file/gaxitinuwov.pdfIn PDF document text
    • https://clubkdo.fr/img/pics/files/rijodadetegozuwaf.pdfIn PDF document text
    • https://mlspoland.co/files/file/94478613671.pdfIn PDF document text
    • http://goforthegreengolfpools.com/userfiles/file/38275820462.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_off0000bdf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDF7 10788 bytes
SHA-256: c5e71082f0f7573a25f7f685c233984a9d197ed4e5f8914c9ce2b81ee89deafa
font_01_sfnt_off0000d66e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD66E 17560 bytes
SHA-256: 3bf253f5067b5dd6118c2b04138471d2dcc05a642895e4f0e928639eeebb7f05
font_02_sfnt_off00010434.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10434 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1