Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5955ea5df2dce61…

MALICIOUS

PDF

84.9 KB Created: 2021-08-21 07:14:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: eea7255cb8be6f866a6d9d8540d2d369 SHA-1: dcac3d1aff72b03b141a463d0ccbef953872f9a3 SHA-256: a5955ea5df2dce61c5702868fc592c74f53e2cddfeb6503ecdaa1d607846e9bd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs and links to compromised WordPress sites, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the links and the heuristic firings point towards a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://ketchas.ru/uplcv?utm_term=formula+productos+notables+binomio+al+cubo PDF link annotation
    • http://ubestsports.com/imager/files/20210609030352.pdfIn PDF document text
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/k39mj5rtep38vohter5d48e362/femigusekegojaf.pdfIn PDF document text
    • https://barcelonacentremedic.cat/files/galeria/files/72235150566.pdfIn PDF document text
    • http://kapsalonvogue.nl/files/file/wetajumukaxiv.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/nosinixusibijijofom.pdfIn PDF document text
    • http://biosurfest.com/userfiles/files/rugiloludur.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/0f3a7967e64defe4fe36ba6a82900637/bufowexulese.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/valadarivetudipetu.pdfIn PDF document text
    • http://werder-ritter.de/UserFiles/File/9889316100.pdfIn PDF document text
    • http://fotossc.pl/_files/file/viferivenofawukekafuket.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f9b553507---fafijasuzulopogadosose.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/webesirajige.pdfIn PDF document text
    • https://magiccat.pro/ckfinder/userfiles/files/60420307129.pdfIn PDF document text
    • http://westernmaki.com/uploads/files/lawewipik.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7e50c7ea73---baxujexudatuvasifoj.pdfIn PDF document text
    • http://salt17.com/userfiles/files/25137046778.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/7bacc0eb2047642e9a4bb061079e499d/67483371992.pdfIn PDF document text
    • https://bistakalikotenetwork.com/userfiles/file/82721014944.pdfIn PDF document text
    • http://skulpt.in/admin/uploads/file/miruk.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/k7jkn9hmcvqs1gvku89b6sk2vk/86068007616.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/58720462630.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160a1adbcbf00a---bedupukopi.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_off0000e4c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C8 10892 bytes
SHA-256: e0e99fff2f3761cbc5e53bf3dabfcaf930d21f5fcbc6c7aa79e3d25d6e6d217d
font_01_sfnt_off0000fdb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000115c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115C9 18308 bytes
SHA-256: f205e3000377e0022684d5cc0e56b064b6ac829618c5d628f5a3fa1000958e8f