Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9c8923439ca5950…

MALICIOUS

PDF

79.5 KB Created: 2021-09-10 19:56:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7e3bc8d25ec9312f6859592021b5bf73 SHA-1: e1e03e86a9d397dfcafc41089f3c2f52865fa76c SHA-256: b9c8923439ca59508039ca2252bb7878f2bab7a4293cea9f6307ad2288c075a5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to PDF files hosted on various domains, some of which appear to be compromised CMS upload directories. The primary purpose seems to be directing users to external malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://dalyanestate.com/userfiles/file/54289575633.pdf In PDF document text
    • https://anandalaya.in/resources/file/telod.pdfIn PDF document text
    • https://michelbarbot.com/upload/files/32171784313.pdfIn PDF document text
    • http://vietkinggroup.com/uploads/userfiles/file/71986122347.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/kcm8cmbubf4gka6n6tosehnair/nofajokamazamanikujusela.pdfIn PDF document text
    • http://eamenfaraz.com/cache/fck_files/file/26219633202.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/jurosojekebasewuz.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/74918438902.pdfIn PDF document text
    • http://methese.com/upload/files/69472380712.pdfIn PDF document text
    • http://mirsistem.com/depo/sayfaresim/file/sexurafagivibovikugog.pdfIn PDF document text
    • https://mancomunidadvaldizarbe.com/userfiles/files/82846393555.pdfIn PDF document text
    • http://scro.ru/pic/file/vumixizotekuxogep.pdfIn PDF document text
    • http://htygroup.com/upload/files/musigiposawikep.pdfIn PDF document text
    • http://officeharbor.com/pdtInfo/xogepezuxogugi.pdfIn PDF document text
    • http://ephtour.com/FileData/ckfinder/files/20210902_ACFEB5AC49FB011E.pdfIn PDF document text
    • https://u15.ch/ckfinder/userfiles/files/bifafabigerebewejaget.pdfIn PDF document text
    • http://donaldnathanlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/157648904.pdfIn PDF document text
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/53bciql88oquev8sqt9bbo4520bar19b/wukavin.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138c91a25a1e---tudafovodenezi.pdfIn PDF document text
    • http://argyleliquidations.com/userfiles/files/37046716825.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/mukuru.pdfIn PDF document text
    • http://joomlacode.org/fckeditor/editor/filemanager/img.php?file=file/37134123620.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/95061561032.pdfIn PDF document text
    • http://jenan.com/ckfinder/userfiles/files/82623344127.pdfIn PDF document text
    • https://baoyi-chuck.com/ckfinder/userfiles/files/29883418336.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=short+stories+on+linePDF 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_off0000d788.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD788 16544 bytes
SHA-256: 7235a017b6ebaa44618f7881f2e6e25628ac83a309299477bd944fd68d407264
font_01_sfnt_off00010226.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10226 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A3D 10120 bytes
SHA-256: 5c23eaf3d0c23d64b45fa33a183b5fd847563831d87ed2d6b18b4b48a8bbb2d2