Malicious PDF — malware analysis report

Static analysis result for SHA-256 639a7a409f3a893c…

MALICIOUS

PDF

80.1 KB Created: 2021-09-17 01:43:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7321559f156bb174a42c3bcc29debd65 SHA-1: ed9493164cbd6c1e9d345ac10ee82e1a08954946 SHA-256: 639a7a409f3a893ccc7c05e6b038c77149cd04f3154e97bc3f44a36e3eea245b
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM and the numerous external URLs suggest a phishing or link-farming scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 6

  • 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.
  • 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://crewmak.ru/uplcv?utm_term=english+file+b1+fourth+edition+pdf+free+download PDF link annotation
    • http://portableandcool.com/files/files/dufolari.pdfIn PDF document text
    • http://eichler-kammerer.de/nazarimenidojunaka.pdfIn PDF document text
    • https://vonia.mikludava.lt/images/files/binopi.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/boxebexipiki.pdfIn PDF document text
    • http://tdbm.vn/upload/files/64913272653.pdfIn PDF document text
    • http://wonderpanel.com/app/webroot/img/file/8098969504.pdfIn PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/51403671974.pdfIn PDF document text
    • https://limblength-sldf.com/userfiles/file/xomadabefololanawet.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/sikejajunewanasafubo.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/8d9abebc7874df8482a58e3523812256/64953510237.pdfIn PDF document text
    • http://phonphangschool.com/upload/files/sesexipeximewebo.pdfIn PDF document text
    • http://stcforanebanglore.smcim.com/www/js/ckfinder/userfiles/files/25910595078.pdfIn PDF document text
    • https://profesa.net/userFilesfile/simofev.pdfIn PDF document text
    • https://quangcaomattroi.com/uploads/news_file/43594799434.pdfIn PDF document text
    • http://shahgrp.com/uploads/jonajazakifirisudifota.pdfIn PDF document text
    • http://www.radio-kum.si/data/files/kezopajibikuzon.pdfIn PDF document text
    • https://scmsgroup.org/ckfinder/userfiles/files/xitav.pdfIn PDF document text
    • https://certifiedcollisionrepair.com/home/cert/public_html/ckfinder/userfiles/files/88628412963.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/95541749289.pdfIn PDF document text
    • https://nutstudio.it/userfiles/file/ladazagak.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/9feb69e60cf8af46126db85ad0b54edc/nosixavusubelovesoruper.pdfIn PDF document text
    • http://zanethompson.com/userfiles/file/30732548701.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/54252287026.pdfIn PDF document text
    • http://bowenlawmt.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/93119092225.pdfIn PDF document text
    • http://gojjang.com/uploads/files/13211290050.pdfIn PDF document text
    • https://maffart-guy.com/userfiles/file/28131926166.pdfIn PDF document text
    • http://autolavaggiocraparotta.it/userfiles/files/31110212357.pdfIn PDF document text
    • https://camelcarpet.org/d/files/zeliredugodu.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_off0000cfee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFEE 18652 bytes
SHA-256: 0143bfbfa21c8908176581ee42c096cbaddb47f562c4115ac78686f79f146e12
font_01_sfnt_off000100d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100D3 11136 bytes
SHA-256: 9a836f0cb8647afdd7af544b69076fe41c753d109dc798a7372537df695ea863
font_02_sfnt_off00011a73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A73 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1