Malicious PDF — malware analysis report

Static analysis result for SHA-256 485fe1e9a54fb537…

MALICIOUS

PDF

70.8 KB Created: 2021-10-01 16:10:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: e2bb67ba13782513d32e8888a40f045a SHA-1: 279ba12eeadedfa41bc435afec36c043c9f2f0e8 SHA-256: 485fe1e9a54fb537a8c5c3c72adb29b3872d69a49d4ff1cdb314d1ac03a2e8db
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The `wkhtmltopdf` authoring application suggests it may have been generated programmatically for mass distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://cructi.ru/uplcv?utm_term=crafting+and+building+minecraft PDF link annotation
    • http://kcemsp.org/upload/editor/file/35834282555.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/tulur.pdfIn PDF document text
    • http://sztarmedia.hu/_user/file/xovekegukituvufesowix.pdfIn PDF document text
    • https://taflanelektronik.com/img/userfiles/file/23961780820.pdfIn PDF document text
    • https://horacebatten.com/ckfinder/userfiles/files/22735976901.pdfIn PDF document text
    • http://www.srijonihealinghome.com/fckimages/file/fukugewoze.pdfIn PDF document text
    • http://pcserviszlin.cz/ckfinder/userfiles/files/33936743520.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615070b9212e8---4800019157.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/1f4d6bc902e4bb5001218a3b6c4206a6/lonowe.pdfIn PDF document text
    • https://die-elke.de/cms/elke_page_files/file/nobozamejud.pdfIn PDF document text
    • http://cec-intl.ru/app/webroot/files/file/gikunakekugej.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-28/20210928005143935086.pdfIn PDF document text
    • http://ledseoul.com/userData/board/file/dopivutegovuki.pdfIn PDF document text
    • http://lhdrum.com/User_File/UpFile/file/20211001192244_dm96aWw=.pdfIn PDF document text
    • https://greenfuturevietnam.com/Upload/files/79262442875.pdfIn PDF document text
    • http://sowa-architekci.pl/userfiles/files/vupifuraxiv.pdfIn PDF document text
    • https://jobtiara.com/files/files/zomipejojanosafukorizezaf.pdfIn PDF document text
    • http://www.synagoge-stommeln.de/ckfinder/userfiles/files/14368947985.pdfIn PDF document text
    • https://promenade-perpignan.com/userfiles/file/vabot.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/db304cf3999cedde7087e69db523fd80/5901205995.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021092816521983.pdfIn PDF document text
    • http://findusafranchise.com/files/files/tukifixevedafe.pdfIn PDF document text
    • https://mokhalasati.com/userfiles/files/vuvovukosotubal.pdfIn PDF document text
    • http://tonioloclaudio.it/userfiles/files/15774938271.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/b69797de5d925f2b3509bb0fb870c01a/37843433877.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_off0000b1ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA03 10800 bytes
SHA-256: 2cda6cf58bc0c2a9f2b48e3d3670d12d81412113bd661cad54fcfd2db6d67b9c
font_02_sfnt_off0000e2a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A6 17040 bytes
SHA-256: 3195b38e43ad11385c85bb861912badb521edc2a6961bcf66a76eec4451135a5