Malicious PDF — malware analysis report

Static analysis result for SHA-256 2738dfc6f757d797…

MALICIOUS

PDF

82.3 KB Created: 2021-09-11 12:14:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a11ea6e2a9d212ccfaef86cb3523b913 SHA-1: f7cc0e7b7914055bd071ce4da24fb86b9e52cf95 SHA-256: 2738dfc6f757d797decaaaca3e94bca241d72441fc3375f5cfdf6c72760f3e30
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically points to the document acting as a link farm hosted on disposable domains, with numerous links to other PDF files. The embedded URLs, such as https://smidgel.ru/uplcv?utm_term=gmd+immersive+mode, likely serve as entry points for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://smidgel.ru/uplcv?utm_term=gmd+immersive+mode PDF link annotation
    • http://kaies.cn/upfiles/file/39718058814.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/29559107361.pdfIn PDF document text
    • http://wmsone.com/eimages/file/lexazamuwo.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1612ee38392f25---xapaganaxizumanodage.pdfIn PDF document text
    • http://hanshintech.net/data/file/zotedujutijikozufaf.pdfIn PDF document text
    • http://rszm88.com/upfolder/e/files/20210906150454.pdfIn PDF document text
    • http://kingsfci.com/userfiles/file/xumonejeganot.pdfIn PDF document text
    • https://casasholidays.com/scgtest/team-explore/uploads/files/fejefore.pdfIn PDF document text
    • http://ave-france.com/pics/files/nenuwiposuzozozoxo.pdfIn PDF document text
    • https://maharajganjtimes.com/assets/ckfinder/core/connector/php/uploads/files/4206689438.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1613b40ed1e6df---91409583283.pdfIn PDF document text
    • https://kingwaterpure.com/ckfinder/userfiles/files/kizisis.pdfIn PDF document text
    • https://bold-iot.com/uploads/files/202109070202093691.pdfIn PDF document text
    • https://nabijdefossa.nl/upload/files/wolidimi.pdfIn PDF document text
    • https://copperscrap.wasteequipment.net/ckfinder/userfiles/files/lixilaf.pdfIn PDF document text
    • https://paroles-vives.com/ckfinder/userfiles/files/14448036065.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/21039350657.pdfIn PDF document text
    • https://apc-algercentre.dz/ckfinder/userfiles/files/44724652220.pdfIn PDF document text
    • http://chinhsuasolieu.com/media/files/dedikorafojab.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/26811716310.pdfIn PDF document text
    • http://nollve.com/img/editor/image/file/mubovegifesokuzi.pdfIn PDF document text
    • http://cpbnatation.fr/fckeditor/userfiles/file/43296829013.pdfIn PDF document text
    • https://giridhareye.org/ckfinder/userfiles/files/86365676065.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/jevapopamilixik.pdfIn PDF document text
    • http://baozhaopharma.com/upload/files/85431586988.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_off0000df16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF16 17552 bytes
SHA-256: 80d851c1b5d70380779c9f6d7994085344f2dfeddd6f288cea327d0b1f8d121e
font_01_sfnt_off00010d0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D0C 10104 bytes
SHA-256: 0afe19c0500cbe8b5f4486938b57d9d4dbe684c0ffd0524ca07b819b2f0014c4
font_02_sfnt_off000123a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1