Malicious PDF — malware analysis report

Static analysis result for SHA-256 435fcd39bded2136…

MALICIOUS

PDF

76.6 KB Created: 2021-09-01 04:12:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 35530f27f689b410957a99eade90304c SHA-1: cf74534cb36b1428e27e6ea05d54825c31b3154f SHA-256: 435fcd39bded21363be3c3ed46b04f13f5b7ab375efcdedd329432df11fc9be9
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to multiple compromised websites and disposable hosting, suggesting an attempt to distribute malicious content or conduct phishing. The presence of embedded URLs and the nature of the heuristics indicate that the document is designed to redirect users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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://msvadba.ru/files/file/56250846861.pdf In PDF document text
    • http://agisma.ru/files/pages/files/kasomagokirejenebi.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b80e705feb0---koladi.pdfIn PDF document text
    • http://jfhcoaching.nl/userfiles/files/18529884851.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/ac167671463ebfc6a925e151b68c653c/beligelululujas.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609b205c2ec6d---98048500867.pdfIn PDF document text
    • http://baaningdoi.com/file_media/file_image/file/65617879950.pdfIn PDF document text
    • http://kentcliffordreunion.com/clients/a/aa/aa84b18e55fac3ff3c25336c5005d9e5/File/kumuleleredo.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c29fa617079---dudajasaxebefafoxupirul.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160bfe72f9da03---mulebif.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ddd75f986f5---10594016339.pdfIn PDF document text
    • https://anitt.in/ckfinder/userfiles/files/45017702032.pdfIn PDF document text
    • https://dp-silver.com/userfiles/file/dixewazofimit.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd3048a632---33676519548.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/bp8jst5g1o4acul3ktmdcrcsmr/52603867439.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/6bag8v9edv6i58g7o9ekqvata4/59012572487.pdfIn PDF document text
    • http://anandamsanyal.com/userfiles/file/tawiranemosubixepewape.pdfIn PDF document text
    • http://npi-management.org/ressource/site-image/files/19753645629.pdfIn PDF document text
    • https://emauto.lv/index/images/up/file/89581461612.pdfIn PDF document text
    • http://thicongdiennuocmiennam.com/uploads/files/23604759430.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/63f4d1fb73b45905b15b90b13285d95b/20925423482.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/142a02590e9d385b7e57bf045dd7b487/rudikig.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612a9ddceb932---tutoxaxibemamubana.pdfIn PDF document text
    • http://eurekaelearning.com/upload/news/file/fokubufasakagesoxafexi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=drinking+water+and+sanitation+minister+of+india+2020PDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eea60e9d99---bepigififipudebawixigogo.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_off0000c60f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC60F 17360 bytes
SHA-256: f32dc1f14b000061bff99e739f690b8f8ee2b347b240529c70314e6c6f6572ba
font_01_sfnt_off0000f262.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF262 11072 bytes
SHA-256: 40da687619add2dcab1132049cfb18068a99008f40e62a2366fdd8da225f528a
font_02_sfnt_off00010c1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1