Malicious PDF — malware analysis report

Static analysis result for SHA-256 875c3320eb55546a…

MALICIOUS

PDF

71.3 KB Created: 2021-09-17 19:21:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a3a88d3facc6d3c2fe8ac14364fbd728 SHA-1: 45369c2aebd3d50fddc5a6e194cad665a6898b7a SHA-256: 875c3320eb55546a2796eec34cb7acdd1d5a06a941cf1c252f613c4a1553b3e3
126 Risk Score

Malware Insights

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

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to disposable domains, indicating a link farm designed to obscure the ultimate destination. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically calls out this behavior, suggesting the PDF is part of a scheme to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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.
  • 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 http://cauthangdep24h.com/upload/files/fodadanikagasubenakab.pdf In PDF document text
    • https://gesema.com/UserFiles/file/vuretebukabumawujo.pdfIn PDF document text
    • http://grabnerestriche.at/riraribiwogekep.pdfIn PDF document text
    • http://thriftstorewebsites.net/flash/thriftstorewebsites.net/file/56119352929.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/409be182bb00ac1687db301629fca201/kobukubibutakevimivo.pdfIn PDF document text
    • http://hospitalityroyal.com/upload_files/file/64697293038.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/betatudenikitemuxito.pdfIn PDF document text
    • https://aecvfcom.nrgence.com/upload/userfiles/files/kuwavalabogekexagavutane.pdfIn PDF document text
    • http://xn--2e0b30g3uq7pay7m.com/upload/fckeditor/file/tegezenividoru.pdfIn PDF document text
    • http://xn--pr3b03lcdvwu9dpynqkc.com/DATA/file/20210911063826.pdfIn PDF document text
    • https://vico-immobilien.com/ckfinder/userfiles/files/96847332866.pdfIn PDF document text
    • http://119pump.net/d/files/lutinu.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/nilimikijopezarodixifuj.pdfIn PDF document text
    • http://www.gleason.com.au/application/third_party/ckfinder/userfiles/files/rofagi.pdfIn PDF document text
    • http://angerdress.store/ckfinder/userfiles/files/mifolub.pdfIn PDF document text
    • http://pension-erlkoenig.de/img/editor/file/77701654586.pdfIn PDF document text
    • http://xn--80aguejfegacgj0ad.xn--p1ai/pict/file/48019461928.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/138309161.pdfIn PDF document text
    • http://xinghui.co/upload/ckimg/files/202109110357578424.pdfIn PDF document text
    • http://lamexmarket.com/uploads/files/zijoremed.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/xovasafowujulefomin.pdfIn PDF document text
    • https://thic.net/plugin/ce1/ckfinder/userfiles/files/kabadorusisejukizurape.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/segujilozozaxemujepu.pdfIn PDF document text
    • http://quetthe.com/upload/files/65737312229.pdfIn PDF document text
    • http://www.vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/55680285487.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=the+dream+team+apkPDF 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_off0000b58c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB58C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD9E 17028 bytes
SHA-256: 6f581628fa49cd0ee91f6e7f7a669be83713a0e68024d2b297527061e1e768b8
font_02_sfnt_off0000f905.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF905 10184 bytes
SHA-256: 48bd8c8c0c7bc66ff0903a35809654bb7a472d8cf3142b85ed116c5ccb30c072