Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4ebcb2def051bed…

MALICIOUS

PDF

74.9 KB Created: 2021-09-09 23:36:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a0cb8742e1c05ad5c51e6be2b3e43cb6 SHA-1: cfeee1c2618d9ec21af92c59f3712739842b40b9 SHA-256: d4ebcb2def051bed4b17be96582a8a296763182c0aa4f82cfadbc1a2ef720045
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The presence of numerous embedded URLs, many pointing to suspicious domains, suggests a phishing or credential harvesting attempt. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically highlights the use of a link farm on disposable hosting, reinforcing the malicious nature of the document's content.

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://guruamardaspublicschool.com/userfiles/files/feputigov.pdf In PDF document text
    • https://www.verimevzabavu.cz/ckfinder/userfiles/files/pupad.pdfIn PDF document text
    • https://bczenekar.hu/files/file/lenojixumubofaruvejupizig.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613900dc943a9---gudozejupisukomosi.pdfIn PDF document text
    • https://pepinieramontana.ro/ckfinder/userfiles/files/73313729360.pdfIn PDF document text
    • https://epiphanych.com/images/file/80116724490.pdfIn PDF document text
    • http://deleeuwputten.nl/site/data/ws/files/pagiza.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/zokaru.pdfIn PDF document text
    • http://gachbinhduong.com/upload/file/46814243950.pdfIn PDF document text
    • http://psychanalyste-gard.fr/ckfinder/userfiles/files/99883855896.pdfIn PDF document text
    • http://shethof.ch/cgi-bin/dynamisch/file/zolugokumu.pdfIn PDF document text
    • http://tz5168.com/uploadfile/image/2021/09/05/file/20210905_025806_152.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file///83058129141.pdfIn PDF document text
    • http://dobermanncz.eu/files/57580072451.pdfIn PDF document text
    • http://mikol-styl.cz/userfiles/file/luwepiraxobufesaso.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/33902819443.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/46655861382.pdfIn PDF document text
    • http://dieutrimun.myphamkangnam.vn/webroot/img/files/9129098523.pdfIn PDF document text
    • https://feng-shuiworld.com/userfiles/file/21874883172.pdfIn PDF document text
    • https://blugarden.eu/file/vinitinolosazematok.pdfIn PDF document text
    • http://donkaew-furniture.com/ckfinder/userfiles/files/futaxapin.pdfIn PDF document text
    • http://tlproduct.com/userfiles/file/21800264163.pdfIn PDF document text
    • https://pieseautocomenzi.ro/userfiles/file/50108562256.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16138f193c12b2---90353271616.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=windows+7+home+basic+keyPDF 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_off0000c366.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC366 10868 bytes
SHA-256: adc4a985bd245929d930628e6459752be1ddfe9bdab8cdbdff59268c76aef657
font_01_sfnt_off0000dc6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC6E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f480.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF480 16408 bytes
SHA-256: 007e0aec68e3c7b4c4d26a195df1d63d8f7fa160540bb48b917e5f8b8eddbb7f