Malicious PDF — malware analysis report

Static analysis result for SHA-256 75526dd87eb4abcb…

MALICIOUS

PDF

82.4 KB Created: 2021-09-15 19:57:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a71f28f9bc6bc0c171d0e71eb633027a SHA-1: 4c5fbae729bdf79fee3b4438d3ab787c11cbd18e SHA-256: 75526dd87eb4abcbdb1c7457a18109beafc67853e04b0e1ed6ef57047ab7783f
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier. It contains embedded JavaScript and a large number of external URIs, many of which are part of a link farm hosted on disposable domains. The embedded JavaScript likely facilitates the redirection to these malicious URLs, aiming to trick users into downloading unwanted or malicious software.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • 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://medvor.ru/uplcv?utm_term=snaptube+apk+last+version PDF link annotation
    • https://livnica-metalurg.com/images/pages/file/lononukuja.pdfIn PDF document text
    • https://giant-nano.com/app/webroot/userfiles/files/likema.pdfIn PDF document text
    • http://winfielddeli.com/ckfinder/userfiles/files/worexakawube.pdfIn PDF document text
    • http://drcleancenter.com/uploads/files/202109100038387691.pdfIn PDF document text
    • http://unitez.net/images/newtech/files/lifuviked.pdfIn PDF document text
    • https://kimansion.com/uploads/file/kagumigaxi.pdfIn PDF document text
    • http://aygroupmuh.com/image/files/33070004362.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/vks6295ojkrn2k0vbp3qcpvfp7/84835964342.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/tuguweveza.pdfIn PDF document text
    • http://chiangmai-esc.net/user_img/files/pifubulofu.pdfIn PDF document text
    • https://dm288.com/slicice/file/fowedonorinoguwozen.pdfIn PDF document text
    • http://thibangoto.com/app/webroot/uploads/files/57666018992.pdfIn PDF document text
    • http://jeansresource.com/js/ckfinder/userfiles/files/suwebuborufigojajozu.pdfIn PDF document text
    • https://kaowei.tw/image/files/20210905_045004.pdfIn PDF document text
    • http://goldendazzle.com/upload/quangtri/files/70201187089.pdfIn PDF document text
    • https://majubesar.net/contents/files/dutilupegelujutut.pdfIn PDF document text
    • https://cristalensi.com/public/File/9406396540.pdfIn PDF document text
    • http://xinxinhouseware.com/uploadfile/files/kanigo.pdfIn PDF document text
    • http://erbamedica.org/userfiles/files/9116951273.pdfIn PDF document text
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/gopibovufozi.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/11ncinforojg1r4f1r9gt0lsae/60161375558.pdfIn PDF document text
    • https://combrooncom.com/contents/files/49931162020.pdfIn PDF document text
    • http://savoie-outils-coupants.com/ckfinder/userfiles/files/nimovuwifasepiwegedasafeb.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/97302719138.pdfIn PDF document text
    • http://balie.overeembv-profielen.nl/upload/files/55272730251.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_off0000d68c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD68C 10716 bytes
SHA-256: df5f9a223d7a3fe1eb7f08d0fc078511da276b844b6f6690207472ebe6bfbe9e
font_01_sfnt_off0000ef18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001072a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1072A 20028 bytes
SHA-256: 8d2861d2aa7fd47497f6fcd4b3a5fabf66177b5d98c0d6eb85c6f80773039eba