Malicious PDF — malware analysis report

Static analysis result for SHA-256 58a2a8d8b0c3781e…

MALICIOUS

PDF

112.3 KB Created: 2021-09-12 05:01:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: ab7ba310406a1af1e76c15bf8db801d5 SHA-1: 440a5c5ded22184d6aa8da92ccdc62ba31c37b4a SHA-256: 58a2a8d8b0c3781ee2fb7ade2b1381fb3679052bdec540b598136a1f3aff0fd0
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a critical ML classifier flag, and numerous URLs indicative of a link farm, strongly suggesting malicious intent. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports this. The embedded JavaScript likely facilitates the redirection to external sites, which are presented as a link farm to obscure the ultimate destination and evade reputation checks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://invest.pl/userfiles/file/10148410911.pdf In PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/talokesevinumagexer.pdfIn PDF document text
    • http://elektro-galerie-hamburg.de/userfiles/file/87298407716.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/84535001682.pdfIn PDF document text
    • http://oppedisanorobertosrl.com/userfiles/files/pujurowasixevifolim.pdfIn PDF document text
    • http://sovaimm.it/userfiles/files/xakotuzivagaxebar.pdfIn PDF document text
    • https://lamaisonducoeur.ca/upload/editor/file/45130716619.pdfIn PDF document text
    • https://designclarf.it/file/darulisivo.pdfIn PDF document text
    • http://flyingfish-stay.com/userfiles/file/23815222097.pdfIn PDF document text
    • http://mapect.com/upload/fckeditor/file/56319157302.pdfIn PDF document text
    • http://auburn-properties.com/userfiles/files/sijabeterug.pdfIn PDF document text
    • https://forumhrdbekasi.com/webroot/userfiles/files/zawivumumizafevebipute.pdfIn PDF document text
    • http://riverla.vn/uploads/userfiles/file/54677136667.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/rotuvukejadarefav.pdfIn PDF document text
    • https://konferencii.ru/js/ckfinder/userfiles/files/tamupev.pdfIn PDF document text
    • https://interference.ajoda.eu/userfiles/files/15078963503.pdfIn PDF document text
    • https://tebra.si/userfiles/file/53078573360.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/42177502094.pdfIn PDF document text
    • http://sntaviator.ru/ckfinder/userfiles/files/13694697937.pdfIn PDF document text
    • http://dolinakrzeptowa.pl/public/upload/ckfinder/userfiles/files/sitevimabaleramalomepena.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/tosejozi.pdfIn PDF document text
    • http://top-rubber.com/admin/fckeditor/editor/filemanager/connectors/upload/file/delivavefenuko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=bespoke+application+software+examplesPDF 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_off00015269.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15269 10972 bytes
SHA-256: 5097450f15cbd918e1c82e413ce91b92a708081b77d4cc78aa9df3cbbcd45c7e
font_01_sfnt_off00016c08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16C08 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001841a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1841A 18300 bytes
SHA-256: 49e4d34af50af12a84382708a2a3aa7f9996cf9a482bc3d853175887483fa49f