Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b5d0806dda6b122…

MALICIOUS

PDF

71.9 KB Created: 2021-09-17 22:54:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1370252280a539362a29f56a708bd919 SHA-1: 3f4bb32f4f7c3d0aeae83b6c75b95345114be815 SHA-256: 3b5d0806dda6b1221726f339c5eb8e61c3e9c7c76cac438d7ba554231e9923ca
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URLs, many of which are structured as link farms pointing to other PDF files, suggesting a distribution or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to obscure the true destination or purpose by using many distinct, disposable hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://archism.ru/uplcv?utm_term=android+share+wifi+password+with+laptop PDF link annotation
    • http://tainanrup.longi.tw/uploadfiles/files/20210910_115232_4261.pdfIn PDF document text
    • http://kfbma.org/files/fck/file/woranumesojaponejokupama.pdfIn PDF document text
    • http://ebsenglish.net/_UploadFile/Images/file/52595378802.pdfIn PDF document text
    • https://biblioteka-koneck.pl/ckfinder/userfiles/files/zamaxozixesekuk.pdfIn PDF document text
    • http://yunnanyingxiang.com/ckfinder/userfiles/files/berodukekodob.pdfIn PDF document text
    • http://matsusushionline.com/uploads/files/2778911007.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/0800850b61b9f59ec80076dfa63ea9ec/muripabokizof.pdfIn PDF document text
    • https://tktravelkorea.com/FileData/ckfinder/files/20210914_A6F6ECF2EB075ADF.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop/contents/67918705761.pdfIn PDF document text
    • http://rideabikenews.com/user_img/files/11984009297.pdfIn PDF document text
    • http://shahgrp.com/uploads/82300709673.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613a91d64cdcb---lajane.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/88017511022.pdfIn PDF document text
    • https://strongpointmarketing.net/userfiles/file/wisopopaf.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/20399513096.pdfIn PDF document text
    • http://madinagirls.com/easydo%20v2.00/files/uploads/lewemivafedezepebiditex.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/96771696452.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/lemojatawewexag.pdfIn PDF document text
    • https://saleskerala.com/ckfinder/userfiles/files/nuwadonos.pdfIn PDF document text
    • http://oresteruggiero.com/userfiles/files/lidovukedavotivokigipa.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/82830548825.pdfIn PDF document text
    • http://smsgurugram.com/miet/assets/files/64555475947.pdfIn PDF document text
    • http://xn--elementy-zczne-kwb98g.pl/media/file/20093913485.pdfIn PDF document text
    • http://casavacanzesanvito.eu/userfiles/files/wowusozebipomuka.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/55050616225.pdfIn PDF document text
    • http://mfo-fond.ru/ckeditor/ckfinder/userfiles/Images/files/pazovawomadutugepofowo.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_off0000b8a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8A9 10660 bytes
SHA-256: 3ec6bec4087f385fbad15bec420d90b3e23de27f19ea4bb13ae1025a68349a82
font_01_sfnt_off0000d110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD110 15980 bytes
SHA-256: 444d18fbe5b1b597bc772c227162ef7cf75edfab277fdc02214ae4c457956a6d
font_02_sfnt_off0000f99d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF99D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1