Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4d22629952da8ce…

MALICIOUS

PDF

77.9 KB Created: 2021-09-01 16:20:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b653d008ad0b2d9082f93db19b2d1968 SHA-1: 5cbd7e12fa2ca3bba2874b7ebad58feb0b7a1932 SHA-256: a4d22629952da8ce3da5cd1f1640360f3e7a8ddfeb8a91ffa900937d8336c807
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://raegcafe.com/uploads/files/48664872457.pdf In PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609891ef27726---fomikum.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/upujttvnetj223fd982avmgts0/33823695018.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1580b17309---17697757939.pdfIn PDF document text
    • http://atthaya.com/file_media/file_image/file/62824513524.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/i21dpn557dj7ljbddb2kaonj63/83205832723.pdfIn PDF document text
    • http://summithighschool1958.com/clients/71652/File/fabafarilurusem.pdfIn PDF document text
    • https://ltssinternational.com/res/wysiwyg/file/sapekutowifaxavisexiga.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/rosawozutene.pdfIn PDF document text
    • http://faradtvandor.hu/picture/userfiles/file/91131942474.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607f05c6e2126---wikobaxududi.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/303456a3e50ae9f67e2d7eb83ad0a1e5/61882110198.pdfIn PDF document text
    • http://safeabortionnepal.com/userfiles/file/50535591210.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1aa51bc14---96054906076.pdfIn PDF document text
    • https://nevisnews.com/userfiles/79732210756.pdfIn PDF document text
    • http://ainut.fi/userfiles/file/sizexizitetiwi.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a07bcb016c4---kinaxomemeli.pdfIn PDF document text
    • http://funke.be/data/file/40001493094.pdfIn PDF document text
    • https://hgqq.hk/tony/churchofgod/ckfinder/userfiles/files/zokagozalimexojed.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/6930822ebe840dbc62194bc27a466972/9414185058.pdfIn PDF document text
    • http://ourconn.com/userfiles/file/202108181307512418.pdfIn PDF document text
    • http://regalmotors-jp.com/js/upload/files/dibatosodo.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/4de4dca22b51ad3c8d150fc86e13e388/91138361266.pdfIn PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160849dd15d2ce---84801631385.pdfIn PDF document text
    • http://wpscrm.in/uploaded_files/userfiles/files/kezulomibefofidisi.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/55a10f8b84d48e003013ebdcf1df6e7b/14879125452.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=counter+petition+for+dissolution+of+marriagePDF 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://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_off0000cb84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB84 10972 bytes
SHA-256: dac17c438188dd68cd7333a155b8d0b7b880be663449d332a7be4c851ca3bc9b
font_01_sfnt_off0000e4c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fcd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCD8 17332 bytes
SHA-256: 42feef5a215f2a963987a950eb55e6ecdb5929c9caffc0276f1b4e78b466e2d9