Malicious PDF — malware analysis report

Static analysis result for SHA-256 437f1fd621f1d42a…

MALICIOUS

PDF

73.2 KB Created: 2021-09-25 04:17:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d57b8bcc88550d17b7d9d8b056e32265 SHA-1: ea710722524995cb7448e69dd8cb1b877bce8ca7 SHA-256: 437f1fd621f1d42ab07b4d94f8b003d23e139d07da6eb2dfa818282427cc69e5
126 Risk Score

Malware Insights

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

The PDF contains numerous external URLs, with one specifically identified as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of embedded URLs suggests an attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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.
  • 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://catamma.ru/uplcv?utm_term=shooter+film+cast PDF link annotation
    • http://tiramisu-o.com/yamituki-n/uploads/files/fiwabuvo.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/33339950484.pdfIn PDF document text
    • https://forssah.co/userfiles/file/sozapotijolewaz.pdfIn PDF document text
    • https://nedimgame.net/calisma2/files/uploads/96652049157.pdfIn PDF document text
    • https://baongochoa.com/upload/file/26215617457.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/57299474293.pdfIn PDF document text
    • https://marathonblainville.com/userfiles/files/17814994605.pdfIn PDF document text
    • http://kdsonline.org/userfiles/file/vuvunapusezamuvajakari.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161423cb73994e---60583645258.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/xunogawadujova.pdfIn PDF document text
    • https://gkscam.com/userfiles/file/50355596535.pdfIn PDF document text
    • http://chiangmai-clean.com/user_img/files/7979124151.pdfIn PDF document text
    • https://freshchannels.com/home/sites/freshchannels/public_html/ckfinder/userfiles/files/kevifa.pdfIn PDF document text
    • http://wintec-samu.hu/uploads/files/wosunebonoje.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/3778300871.pdfIn PDF document text
    • http://oticonshop.com/ckfinder/userfiles/files/21856698230.pdfIn PDF document text
    • https://navliecky.net/userfiles/file/45869182341.pdfIn PDF document text
    • https://bselink.com/userfiles/file/14190238052.pdfIn PDF document text
    • http://filtrydokoparek.pl/img/all/rovebitilaximigugupejigu.pdfIn PDF document text
    • https://semut73.com/contents/files/deserosurut.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/22064589750.pdfIn PDF document text
    • https://mingyi-lock.com/data/file/userfiles/files/gamipatanelabogujegifi.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/vutuzenolozuwawewuxoxanej.pdfIn PDF document text
    • http://hoanhaochemical.com/uploads/files/rukowidudikokuwim.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_off0000b72e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB72E 18616 bytes
SHA-256: cee6513f7c18fe7b35be03d69b1dff46a43f30d31c09109ea28c53c86f5cd1d6
font_01_sfnt_off0000e6d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6D4 10572 bytes
SHA-256: 6b6e42022de87d3bd1de23de5418c8af519e035dd8cd11179fca1c0a094deb2b
font_02_sfnt_off0000fef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1