Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ffc31d3c1a6b527…

MALICIOUS

PDF

77.9 KB Created: 2021-09-04 04:47:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e64aff4cc24eded86e15992aabb0605a SHA-1: 008d150c01d703e1acaf411754ff3264ba1e8224 SHA-256: 4ffc31d3c1a6b5278f7f3b8bbc8523928429473f54ca7b6f9d3f9e171f84ec23
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites. The embedded URLs suggest an attempt to lure users to external content, likely for phishing or to download further malicious payloads. The document body is heavily obfuscated and appears to be generated content rather than user-readable text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd15d88b13---meduzovowo.pdf In PDF document text
    • https://broadcasthub.com/ci/userfiles/files/98052495559.pdfIn PDF document text
    • http://slsnn.ru/content/file/6287638781.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16082c1b6c4bf0---wexonujigo.pdfIn PDF document text
    • http://imreelectric.sk/uploads/file/6081274356.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/misijumijov.pdfIn PDF document text
    • http://straps.by/ckfinder/userfiles/files/nomawesesuvazunik.pdfIn PDF document text
    • https://lightingsystemscol.com/wp-content/plugins/super-forms/uploads/php/files/c25a815221140f15d9068128a50278ea/jivofid.pdfIn PDF document text
    • https://airshow-bg.com/file/bimixip.pdfIn PDF document text
    • https://ximatinhdongnai.com/app/webroot/files/images/pages/files/84253470395.pdfIn PDF document text
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gosunidojoxaparutevu.pdfIn PDF document text
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/ee8d41fb19e1622b4a31ba66857740d5/56883264901.pdfIn PDF document text
    • http://norilskgu.ru/userfiles/file/46723834070.pdfIn PDF document text
    • http://phutunggiahungoto.com/uploads/files/lajazegufosugif.pdfIn PDF document text
    • http://orrizon.ru/images/file/domojaruziwurolexo.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fd62c1458e5---3017964943.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160f3db5a05641---18255990963.pdfIn PDF document text
    • https://xn----8sbcehyodmtf1czh.xn--p1ai/userfiles/file/petidavujilaz.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd59394c24---185411592.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/xekamukaxalusigegomuwow.pdfIn PDF document text
    • http://zoltysnieg.pl/pliki_wyswig/files/sadigupibopule.pdfIn PDF document text
    • http://24horasnoar.com.br/ckfinder/userfiles/files/zosut.pdfIn PDF document text
    • http://planetamama.ru/files/file/5857915201.pdfIn PDF document text
    • https://nutrishop.in/ci/userfiles/files/4589262159.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=perpendicular+bisectors+and+angle+bisectors+of+a+triangle+worksheetPDF 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_off0000c9e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9E4 17420 bytes
SHA-256: e580bed77e71fc96d5acc2808483ad62aaec71cda2437e68d9c828cfeb7c8179
font_01_sfnt_off0000f6ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6EF 11320 bytes
SHA-256: c76c5de21be485b132f32746e79de9c1e80ba1cd512f0ad41030470c38d712b1
font_02_sfnt_off00011125.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11125 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1