Malicious PDF — malware analysis report

Static analysis result for SHA-256 4230c7563a520cf4…

MALICIOUS

PDF

96.1 KB Created: 2021-08-12 06:14:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8728ed79456e714f09552f7c4369d5c9 SHA-1: 01c05f8d16baca13266a52daab80466b34b1b7f4 SHA-256: 4230c7563a520cf42b2563d3dfbe25b023ff8c3a0e5e79f14f8aaac7249c15ab
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised websites, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm on disposable hosting and pointing to compromised CMS uploads. No scripts were extracted, but the overall structure suggests an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 5

  • 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://coretry.ru/uplcv?utm_term=what+strategies+did+women%27s+suffrage+use PDF link annotation
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/161030a094ad02---bivodijedatukuz.pdfIn PDF document text
    • http://ekbdrive.ru/ckfinder/userfiles/files/besatizafoloberogisajili.pdfIn PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/16071bb6db2f4f---83331455327.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095445e494a6---22901355384.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/904466c57a0415549e123eddd1085a1e/2285972474.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abd28069dd6---44325071047.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/89578171658.pdfIn PDF document text
    • http://gesundimjob.at/images/content/files/77273345401.pdfIn PDF document text
    • http://zartmobilia.com/userfiles/file/20210721065408.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/24212909152.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/97351270878.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092caf19d4ab---70409751997.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/pnh1p0d4euikc8s7ppdbgfv0l3/25414692110.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1609854fb9f929---tuzosopibesitozatem.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a40641c6c66---roporagozudikezoniwexura.pdfIn PDF document text
    • http://yilip.net/userData/board/file/91459872987.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c21daf8d6d8---13507701793.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/20152156431.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a06bce5cf1f---11249440179.pdfIn PDF document text
    • http://techbis.pl/files/file/34130176490.pdfIn PDF document text
    • http://steelfurniturecn.com/d/files/22554597141.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/52118603981.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_off000112aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012abc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ABC 17412 bytes
SHA-256: 29ca4f2a1b438120af2d8e65bb0d0aeaf63e18f63aa8d8c942561b3c216e5de4
font_02_sfnt_off0001583a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1583A 10968 bytes
SHA-256: c4527510090cb1a01c16dc19a6aa219c130446eb8e3520cfa393ef656327c367