Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ad37bf32edc1a7f…

MALICIOUS

PDF

76.4 KB Created: 2021-09-10 07:22:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 94357627db2b2dc537cfae061273fc8e SHA-1: ebea1b66fbab8d898143e96200f697a7464e2848 SHA-256: 4ad37bf32edc1a7f470cb2a76f120f0cbfab6c8ac5b1b6bdb76e2b4b20ceb543
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to suspicious domains and appear to be part of a link farm designed to redirect users. The `PDF_SEO_DISPOSABLE_LINK_FARM` heuristic confirms this behavior, indicating a high volume of links on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 http://queenart.kr/userData/board/file/5518604161.pdf In PDF document text
    • http://draftingfloorplan.com/ckfinder/userfiles/files/tulonuwidekukozikexuv.pdfIn PDF document text
    • http://tecniagua.es/uploads/ckfinder/files/litibesojaru.pdfIn PDF document text
    • https://vas-vill.hu/userfiles/file/97742105426.pdfIn PDF document text
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/fevitafiluzexomuxunanika.pdfIn PDF document text
    • http://njchemland.com/upload/files/pevolofisumavexesogox.pdfIn PDF document text
    • http://minhtoangalaxyhotel.vn/app/webroot/files/ckfinder/files/tasezekegokurejovezofus.pdfIn PDF document text
    • https://suacuachuyennghiep.com/uploads/files/xamisadesuwulun.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/a0df619b96287c6a0e4056fd2557c9a7/gunozazexik.pdfIn PDF document text
    • http://zechnerbau.at/images/content/files/70026441852.pdfIn PDF document text
    • http://www.giuseppe.ru/ckfinder/userfiles/files/88155691413.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/jazef.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210905183633.pdfIn PDF document text
    • https://gazeta-msp.pl/user_files/File/42719105876.pdfIn PDF document text
    • http://phuketdriveschool.com/userfiles/file/8706525909.pdfIn PDF document text
    • http://mastervin.ru/files/file/14930836126.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/161382912a42fa---27885721407.pdfIn PDF document text
    • http://www.skk.com.hk/admin/ckfinder/userfiles/files/53151039060.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/17915486094.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/pafabupolixitenekebonoja.pdfIn PDF document text
    • http://www.coverseg.com/uploads/ckfinder/files/34527168227.pdfIn PDF document text
    • http://canphantich.net/Images_upload/files/sosevokutojenez.pdfIn PDF document text
    • http://cosmosimpex.com/app/webroot/ckfinder/userfiles/files/jawenisoginida.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/wakofapurudozumaverof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=love+island+south+africa+season+1+episode+1+watch+onlinePDF 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_off0000c45a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC45A 10976 bytes
SHA-256: 078060174376ff5aeae0ca71ad6c0c9749daaddcb7de47ca2a4f16871b15a0e4
font_01_sfnt_off0000dde1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f5f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F3 17948 bytes
SHA-256: 871a2b45b7d68eef14346d559436f0a245ed43e8f85e4fad5d79bfc4666ad084