Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8439b1bac1b276a…

MALICIOUS

PDF

69.0 KB Created: 2021-09-27 20:14:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 56b27b62a06dc8bac237d4816d09278f SHA-1: fa513d6bd73e3c3405094a38f6a753b7d4633c2f SHA-256: c8439b1bac1b276a3a210a9a7e9982276c8e65c314f9d931158a4970a66185db
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. It contains numerous embedded URLs pointing to external sites, and the PDF structure suggests it functions as a link farm, likely to distribute phishing content or malware. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination or host multiple malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://mayinluatudong.com/uploads/userfiles/file/kupozavodurolodud.pdf In PDF document text
    • https://reklama71.ru/upload_picture/81404023424.pdfIn PDF document text
    • http://tlumacz-lipno.pl/pdrzewiecki/files/17637156545.pdfIn PDF document text
    • http://pure-chiral.com/upload/files/28100834381.pdfIn PDF document text
    • https://alutat.com/data/file/74705651785.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/7c37898e88d7bccefe6f10c901e84c70/zovik.pdfIn PDF document text
    • https://aaaxxion.info/images/file/95030017958.pdfIn PDF document text
    • http://dga.gr/ILC/img/file/30760895660.pdfIn PDF document text
    • http://fsgzb.com/upfolder/e/files/20210917063752.pdfIn PDF document text
    • https://chilepools.com/contents/files/wilise.pdfIn PDF document text
    • https://szallas-karpatalja.net/upload/82969320759.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/43612564589.pdfIn PDF document text
    • http://dgelc.com/userfiles/file/20210906143220.pdfIn PDF document text
    • https://amthanhanhsangchinhhang.vn/upload/files/66823669837.pdfIn PDF document text
    • http://kahasat.cz/data/file/radage.pdfIn PDF document text
    • https://ginniglobal.com/uploads/file/jazijivinazozazalomebunu.pdfIn PDF document text
    • http://metaglas.kr/userData/board/file/11837420127.pdfIn PDF document text
    • http://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/nerexepolivawujot.pdfIn PDF document text
    • http://www.likoda.com.tw/upload/ckimg/files/62144104098.pdfIn PDF document text
    • http://gaziogluenerji.com/images_upload/files/nuwetixakawoxevimipes.pdfIn PDF document text
    • http://platypusspot.org/uploads/ckfinder/userfiles/files/47554332207.pdfIn PDF document text
    • https://clickbox.ro/images/file/75386401803.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=hopeless+land+mod+apk+unlimited+couponPDF 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_off0000ad5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD5B 10756 bytes
SHA-256: a4c55e63cceae4c8dcd5e45d1c1e9d23ba7e43b874049124900311b39bf8f54b
font_01_sfnt_off0000c60d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC60D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000de1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE1F 15992 bytes
SHA-256: 387418cd364d47b6cd41b012677fa6065879999c6f558580685b7b332de6d2f4

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