Malicious PDF — malware analysis report

Static analysis result for SHA-256 1fb3b387440d3b0d…

MALICIOUS

PDF

70.6 KB Created: 2021-10-03 11:54:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: fb81277e287a2cf56f34cd3f2e48b5ba SHA-1: 45ceca9959413a5814d651c36c6ef0bfd037f18a SHA-256: 1fb3b387440d3b0d73601bc9e614c28163600525f6d0f113d83183a330a1cf3b
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress sites or disposable hosting, forming a link farm. The ML classifier strongly indicates maliciousness, and the presence of JavaScript suggests it may be used to execute further malicious actions or redirect the user. The primary attack pattern observed is the use of a link farm to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

Heuristics 6

  • 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 https://crewmak.ru/uplcv?utm_term=drager+resuscitaire+infant+warmer+service+manual PDF link annotation
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/s0q3tjnb9ph4hecng05oamlp25/59772966325.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16132dd64eda26---ziwex.pdfIn PDF document text
    • https://ripedzn.com/app/webroot/files/fckeditor/file/kulagexodorenukeri.pdfIn PDF document text
    • https://www.vek-bg.com/app/templates/js/ckfinder/userfiles/files/29128091182.pdfIn PDF document text
    • http://rollfactorytogo.com/uploads/files/54991313556.pdfIn PDF document text
    • http://abwalabamaave.com/uploads/files/95589215936.pdfIn PDF document text
    • http://yogaschoolofkerala.com/photos/editor/files/81216948185.pdfIn PDF document text
    • http://we-plus.tw/ckfinder/userfiles/files/58649690835.pdfIn PDF document text
    • http://www.siposferenc.hu/html/varopog.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613c5ecb02a0d---vazezu.pdfIn PDF document text
    • http://xn--2-140-swe8h.xn--p1ai/files/31526193590.pdfIn PDF document text
    • http://tonghuichem.com/upload/files/65546151905.pdfIn PDF document text
    • http://immopolignano.lu/images/33508840359.pdfIn PDF document text
    • http://falegnameriacastiglione.it/userfiles/files/88956344753.pdfIn PDF document text
    • http://abwcrainhwy.com/uploads/files/kaferebijuturi.pdfIn PDF document text
    • https://www.hotelrestaurantmacarena.fr/ckfinder/userfiles/files/libexedapano.pdfIn PDF document text
    • https://jin-hung.com/userfiles/file/tapixetadin.pdfIn PDF document text
    • http://nhasachthunam.com/upload/files/xesurowiruwediga.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/file/18105164466.pdfIn PDF document text
    • http://mlsite.gewoozee.tw/custom/file/badovoj.pdfIn PDF document text
    • https://voxel-avocats.fr/uploads/file/In PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c96e717616---pizavu.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/9a09fd915a56c14442e9e64d9986e21b/4632984055.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_off0000af7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF7D 10812 bytes
SHA-256: 971fd1d7f071710668b62c869717bf9ea3aefc7f47916124fc5286663fe8fceb
font_01_sfnt_off0000c879.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC879 16596 bytes
SHA-256: a8e50b35e965d0b32e15e47de084e9777ea6d1f8b08f59cacffec460101d530e
font_02_sfnt_off0000f295.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF295 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1