Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb8b64d41fc7b558…

MALICIOUS

PDF

75.7 KB Created: 2021-09-09 10:16:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 15526c98046e8da58a8effcd9214ba83 SHA-1: 26813479e9fb706b39e46c1b27a9348c7113228f SHA-256: bb8b64d41fc7b5587b2a1952aad5b62c08a35e6419499b65ac40ba735015565d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to link farms, suggesting a phishing or malware distribution campaign. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://grdr.org/paidel/ckfinder/userfiles/files/9022971147.pdf In PDF document text
    • http://klubalfa.org/img/userfiles/file/56709823683.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/xudilosubekawugim.pdfIn PDF document text
    • http://cleanyachts.it/writable/public/userfiles/file/7589116504.pdfIn PDF document text
    • https://zbmbudomont.pl/userfiles/file/28495491489.pdfIn PDF document text
    • http://sintniklaas.kinderopvangpimpeloentje.be/ckfinder/userfiles/files/xonizubuxobepababawaxi.pdfIn PDF document text
    • http://stefani.cz/fck/file/9632807974.pdfIn PDF document text
    • http://azstorestudio.com/uploads/files/lemedu.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/savezinopozosogaw.pdfIn PDF document text
    • http://mhinflatable.com/upload/file/tuxuxuzuzamivu.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/161354c729927a---6784315947.pdfIn PDF document text
    • http://girc.ncue.edu.tw/ckfinder/ckfiles/files/3016323119.pdfIn PDF document text
    • http://consade.com/userfiles/file/bisolixidudajokesopakufo.pdfIn PDF document text
    • https://printjet.pl/pliki_user/File/nisituzedabotokedi.pdfIn PDF document text
    • http://drsuthichai.com/userfiles/files/sifuguxipava.pdfIn PDF document text
    • http://daiichihousing.net/uploads/news_file/18800213530.pdfIn PDF document text
    • http://horizonpestservices.com/userfile/jupawabe.pdfIn PDF document text
    • https://vidaleve.net/ckfinder/userfiles/files/losamukufenekidizojiziku.pdfIn PDF document text
    • https://hotelharmika.com/assets/userfiles/files/18822943706.pdfIn PDF document text
    • https://perfecthospital.net/ckfinder/userfiles/files/kugezoxex.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135a805c18ab---51870820171.pdfIn PDF document text
    • http://toptoptraining.ru/img/upload/file/85839657757.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/leloveweb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=audio+pro+apkPDF 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_off0000c7d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7D6 16708 bytes
SHA-256: 4e1a2cedfaca5fd3e58218bf80f7ea950011ec6268cb88b6492b447690f9c8c8
font_01_sfnt_off0000f305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF305 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010b1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1C 10008 bytes
SHA-256: 2f8c2748ea0e37247c42772f6c124096cd8d09629ad9b86a70802180b8025ab2