Malicious PDF — malware analysis report

Static analysis result for SHA-256 937bd5572dc993f6…

MALICIOUS

PDF

86.4 KB Created: 2021-08-24 23:45:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a7612ad9c2c1ef7c73a2be519d6dff3e SHA-1: cd1ddfb77b344276fe44ebb6aa0bdf5522b57c40 SHA-256: 937bd5572dc993f603d3441b9ff3b82019fa4f3ca8ea2546edfb0715cb2430cc
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lure users to malicious destinations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the presence of external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://infrive.ru/uplcv?utm_term=duval+county+inmate+records PDF link annotation
    • http://gezond-trakteren.nl/kasteel-doornenburg-img/bestandenfile/2428145202.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/4becaca8835e0bda63e581b3e64cba77/fukododijilibibamabufis.pdfIn PDF document text
    • https://eurotechcorp.vn/admin/webroot/upload/image/files/sidiwixaw.pdfIn PDF document text
    • http://salamino.pl/userfiles/file/26362151107.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607c04dc8a554---57473787686.pdfIn PDF document text
    • http://toshiba-center.ru/uploads/files/6503212111.pdfIn PDF document text
    • http://resurrection-life.net/userfiles/files/56689608936.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160c29c37de135---momuvibopekajuwal.pdfIn PDF document text
    • http://pastoret.it/userfiles/files/xodivodoranubazavog.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/5cec4f97ad2c1c6e741f93b4eb36c32d/lipov.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/95439237643.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074c1669d8bf---70968900749.pdfIn PDF document text
    • http://dichvuhangngay.vn/uploads/image/files/1481129078.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/97eba71158806595a5e0cb1e4136fce1/36118432420.pdfIn PDF document text
    • http://cesmclassof68cheyennewy.com/clients/82478/File/tinovokunizesu.pdfIn PDF document text
    • http://eastendmediation.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dabupifudopupugumitedugup.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/kesekujiwizaxesujane.pdfIn PDF document text
    • https://iwnta.com/userfiles/file/12925593279.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e0360e34f7---12516470903.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/96dc41c035ff03d77703310b64b1ff3d/84233345090.pdfIn PDF document text
    • https://nffcd.org/userfiles/files/4774467327.pdfIn PDF document text
    • http://natpuedu.in/userfiles/file/15476384904.pdfIn PDF document text
    • http://bakoca.hu/files/file/retoded.pdfIn PDF document text
    • https://markiza-trade.ru/admin/ckfinder/userfiles/files/mafasidiviburusagivepol.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_off0000ee37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE37 16860 bytes
SHA-256: 7ab095f2420bf8a9a4d47084e5f68284b68474c1cb225691b857935958f4415f
font_01_sfnt_off00011a0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A0A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013221.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13221 10812 bytes
SHA-256: e3645b383c0afd544d305f915bfe0ddcbc66892e975c0bc36dd960957ed58530