Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8371668fb37b244…

MALICIOUS

PDF

98.5 KB Created: 2021-07-25 13:23:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 8ef927beb08b808d54c21a569d8c8aeb SHA-1: e6d852c9568f126ea0b373d35e1b2a38bd8ffcbe SHA-256: b8371668fb37b2442d071148f1267323b0518a16048c6313f1a956aabe58257f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDF files. The presence of external URI heuristics and the compromised CMS upload link farm suggest a phishing or malware distribution scheme. No scripts were extracted, but the overall structure indicates a redirection chain designed to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9875

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.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085869deafa7---dojujugej.pdf In PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077873976879---lakidenanore.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/812fae3987c791c0af45e0a68f08e43f/kutukolimenilu.pdfIn PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/topoxanel.pdfIn PDF document text
    • http://studiolaviano.it/userfiles/files/mexan.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/m3h8rvqq24cl6cqpa8tq3fiaec/82156963145.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/c320f9130e0ead30fce072c94a67c4a7/fujijezirumegosisonufun.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/f20e4ac009d76ffbfff4c0ed41dd17c9/32156510224.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/cefcadc2da8a1dbe3f0326baf36a0229/59795197994.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/22218367521.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/benabaxafirarazevogov.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/0869d05b6e8c6d89b255b33fcb5070be/55887997089.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/575d0fff281639b6aee5332274f869ef/narimediganajomexexo.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/11035026356.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/93147643583.pdfIn PDF document text
    • http://aapltd.net/userfiles/file/migobela.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/41295401439.pdfIn PDF document text
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bda56c3a20---26650844897.pdfIn PDF document text
    • https://nasikampung.info/contents//files/rajagumulonera.pdfIn PDF document text
    • http://xn--aknmedical-yub.com/uploads/file/tinovunamuxanoxo.pdfIn PDF document text
    • https://www.dartmusicfestival.co.uk/wp-content/plugins/super-forms/uploads/php/files/c87bb34a7f5b0eb2ab3d239cb6dacb08/moveda.pdfIn PDF document text
    • https://standsimulator.com/ckfinder/userfiles/files/lolejowekakegifovu.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/bb5f1a6e68fabb9ddf85e449936fde05/fivov.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b0ba1aec1c1---dajunogarupozosezodoso.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/a7a451beee0881c768c4978d0f0003ff/jodixipatopukozi.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a0cccb4370c27ba7884c1531600708ea/59281288290.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=johnny+tremain+audiobook+chapter+10PDF 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_off00011c8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C8D 17628 bytes
SHA-256: af481f82766e9c9db61346d6f79df747417fa68c45bb4bff16b55f1206eff21d
font_01_sfnt_off00014a86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A86 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001629d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1629D 11176 bytes
SHA-256: f75e4092963397c2bb466b5d73c9038148ea6e3449d5542b205153bb9a96e2b8