Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef8f720055c898a4…

MALICIOUS

PDF

87.3 KB Created: 2021-09-08 22:26:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f175534f2e76a6c4793902c1f05d607d SHA-1: 1ef0e376a7ae94da4a57007e72122f1a7c2f5489 SHA-256: ef8f720055c898a4cd90e09844e49faa1d55f8df0a5937e004c531ff815fd920
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to potentially compromised or disposable domains, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and the presence of numerous external links indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://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