Malicious PDF — malware analysis report

Static analysis result for SHA-256 941c8e940801048c…

MALICIOUS

PDF

84.0 KB Created: 2021-10-08 10:11:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a56e5dbdf5f8c71f7ffa70582f861ae9 SHA-1: ea31865520fd2d537b793bb11f4bb611cb806a69 SHA-256: 941c8e940801048cd57ccc45a848fbc384960f3418dab892cbb7bd610aa05bb2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains and are structured as a link farm, a common tactic for phishing or malware distribution. The document body is heavily obfuscated, preventing a clear understanding of its direct user-facing content, but the overall structure and heuristic firings strongly suggest a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://assofmt.org/ckfinder/userfiles/files/foxerepudirefifimukugo.pdf In PDF document text
    • http://vertex-decor.com/userfiles/file/xejagixotonesok.pdfIn PDF document text
    • http://footstepfloor.com/upfiles/files/dananekuvizor.pdfIn PDF document text
    • https://alkoplast.rs/files/jewuxewojexadabin.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/42182855975.pdfIn PDF document text
    • http://xinyuemu.net/assets/202110/files/20211001100833821863.pdfIn PDF document text
    • https://branchennachweis.eu/userfiles/file/44849089577.pdfIn PDF document text
    • http://2safe4u.cz/UserFiles/File/38021262963.pdfIn PDF document text
    • https://kfmaccounting.com/webroot/img/content/files/wikiwupiberega.pdfIn PDF document text
    • http://life-homeshop.com/asset/uploads/files/69488834523.pdfIn PDF document text
    • http://hoadondientu-ptp.vn/images/ckeditor/files/99228082668.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16134f633befea---puxezumizukonubuw.pdfIn PDF document text
    • http://nutranghongngoc.com/media/ftp/file/kobolud.pdfIn PDF document text
    • http://dekobonner.de/userfiles/file/popegenunujod.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/3459991561.pdfIn PDF document text
    • http://plncse.hu/php_data/file/bujifapixerumaloxonam.pdfIn PDF document text
    • http://sz-frp.com/pic/20210920195229705.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/xujedovonarupabofowafaso.pdfIn PDF document text
    • https://worldpigment.com/image/upload/File/papiwamaveru.pdfIn PDF document text
    • http://dpholding.ru/uploads/files/78066999539.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/57383433599.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/55129753174.pdfIn PDF document text
    • http://metrominicabs.com/survey/userfiles/files/jadufoxoxut.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1615351d5a7f52---fubugubimomirogazadef.pdfIn PDF document text
    • http://plan.msu.ac.th/ckfinder/userfiles/files/54786505558.pdfIn PDF document text
    • http://svazekobciorlice.cz/userfiles/file/21742178343.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=happy+birthday+piano+notes+lettersPDF 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_off0000db89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB89 20612 bytes
SHA-256: 5221996bd993dcfe0c27b9add6165a3d0f8423ae348767df16469accffe38cc7
font_01_sfnt_off00011186.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11186 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001299d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1299D 10732 bytes
SHA-256: 783e9f7897ccbbe82e091e1b6583b661e71a4eab91071e52c4a186dd42d0a5f5