Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8a07e3f7614d6d8…

MALICIOUS

PDF

68.8 KB Created: 2021-05-26 21:18:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 6537a62aef40262dbdbb8d9e5b4465e6 SHA-1: d147bd49d27d710ca07019cdc0dbeba75b2fadc9 SHA-256: b8a07e3f7614d6d8cb4973bd7fbd4958b9bb4257fbf109b73ec02b334ea9b2cb
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier also flagged this PDF as malicious. The primary purpose appears to be redirecting users to potentially malicious content hosted on these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://accessiblevehicleservices.com/userfiles/file/goturabomasi.pdf In PDF document text
    • https://munord.com/wp-content/plugins/super-forms/uploads/php/files/c8c5438c1b6addb840cc237576b17391/dizaxemexugodefole.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/nupnn19tceifup2vurb5tnih22/lemevitixaxob.pdfIn PDF document text
    • http://dnepropress.net/files/file/wozafevevasovemikavolixu.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/ad9e9b60e222d75e035eaa0d7d3cb051/zafibipusuxabobelofow.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1608f8828ee8d8---426909517.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16077a99860bd0---kasazavizasawe.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160913793d759f---73696219075.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16094d8122d268---36764492147.pdfIn PDF document text
    • https://olmitek.by/wp-content/plugins/super-forms/uploads/php/files/00h8rch949mk7d1tq800rq5vq3/15952333494.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aa0999ae62e---mabubejogabijuxari.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609190aae54df---gukuxewovojudapun.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc962af5ab---gesugizelodit.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a66771ae57a---66402510099.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607552670efae---zofurotosisejotif.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=agile+antipatterns+pdfPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1FB 5200 bytes
SHA-256: abc3f0a64dbbe87efb539d32e9f2d9b63c6ed711592df9987cf555784dfc57ba
font_01_sfnt_off0000e3c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3C0 10280 bytes
SHA-256: fd5c0b3d13e60c7f4235a01ad2ada87dacc222d3571e5fc18c136af2d02a04c6