Malicious PDF — malware analysis report

Static analysis result for SHA-256 8013c11a1e236522…

MALICIOUS

PDF

87.7 KB Created: 2021-09-08 22:26:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 74448a09b808cbab50d8e498baa82c9b SHA-1: 52b560c6363945e5b06335cbcacc6f26d1f320ab SHA-256: 8013c11a1e236522bc27e9e2aa94cc7ebb0c7a5aff5a555d70468fae4aa262f1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, one of which is hosted on a potentially disposable domain. Although no scripts were explicitly extracted, the PDF structure and the nature of the URLs suggest an attempt to redirect users to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1613704a525f2d---masidawidaxivumisexufod.pdf In PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16136c95901f04---vufonedorevonok.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/202196455397806.pdfIn PDF document text
    • http://silarperu.com/UserFiles/file/12289330446.pdfIn PDF document text
    • http://spbi.cz/res/file/dekipekid.pdfIn PDF document text
    • http://serbanindustrialconstruct.ro/uploads/files/kakitazadiwepozorekatu.pdfIn PDF document text
    • http://chapelguild.com/images/usr/resurovebinafevatoxoxob.pdfIn PDF document text
    • https://mkontroll.hu/File/polupufadez.pdfIn PDF document text
    • https://bushregenerators.biz/userfiles/files/ravujakedogetudizon.pdfIn PDF document text
    • http://groupelamiri.com/uploads/FCK_files/file/7056454219.pdfIn PDF document text
    • http://vilniausgreziniai.lt/userfiles/file/japoxamalavedowunogaw.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/muwuruko.pdfIn PDF document text
    • http://alhambra.kopanramen.com/uploads/files/fasivogigitamefunopodur.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/5686093934.pdfIn PDF document text
    • http://artediapharma.com/upload/files/23517965382.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/15110840541.pdfIn PDF document text
    • http://sloplast.com/userfiles/files/73691031582.pdfIn PDF document text
    • https://sts-cct.com/app/webroot/userfiles/files/76673020047.pdfIn PDF document text
    • http://gzcil.com/uploadfile/files/nipifosafa.pdfIn PDF document text
    • http://clean-ecology.com/Upload/files/25853427193.pdfIn PDF document text
    • http://newtarrytowndeli.com/uploads/files/pijikujexixedu.pdfIn PDF document text
    • http://schokozentrale.de/idata/83431248802.pdfIn PDF document text
    • https://grafconsulting.pl/Upload/file/32571579352.pdfIn PDF document text
    • https://nullemont.fr/nullemont/ckfinder/userfiles/files/77820668834.pdfIn PDF document text
    • https://mgc.to/sites/web/upload/files/fibefepiliniladu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=mac+os+big+sur+kernel+panicPDF 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_off0000f242.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF242 10776 bytes
SHA-256: edcd271976efb5af19a43ed28befdf36b02a330d09306eb79744287412753732
font_01_sfnt_off00010afa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AFA 18192 bytes
SHA-256: 09eb46bdc0b08b1a74810a6cc9a6456e871c7ab46335b72f2430767d8b221201
font_02_sfnt_off00013a32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A32 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1