Malicious PDF — malware analysis report

Static analysis result for SHA-256 15bf6aadcfc3950d…

MALICIOUS

PDF

80.3 KB Created: 2021-10-12 14:14:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 6d28de00629226e7804ba11eae692c78 SHA-1: 35d268798406f70e60d1e44bc41368554be0d05e SHA-256: 15bf6aadcfc3950d29a9529c0afc86aa9262c4cf323dc1bc968d487a731f5556
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious sites, which are presented as a link farm, a common tactic for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/16155c8f8ad6ac---gulowifubisirukop.pdf In PDF document text
    • http://105chers.netsociality.com/upload/files/xejunofagitef.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/71701869119.pdfIn PDF document text
    • http://sensi-leszno.pl/userfiles/file/widajemusap.pdfIn PDF document text
    • http://euskararenginkana.eus/files/galeria/files/7074308271.pdfIn PDF document text
    • http://bifruit.mk/ckfinder/userfiles/files/56939076729.pdfIn PDF document text
    • http://onnetsolution.in/userfiles/file/doginutap.pdfIn PDF document text
    • http://quimis.net/js/ckfinder/userfiles/files/zubosiwapiwifujefovavum.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/dadaz.pdfIn PDF document text
    • http://laduses.nl/image/file/63799767074.pdfIn PDF document text
    • https://office-agglo-larochelle.fr/userfiles/file/wowavo.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615c08d01d318---wezasirowokazuvagixegefiz.pdfIn PDF document text
    • http://studiotecnicodama.it/userfiles/files/44609018983.pdfIn PDF document text
    • http://juha.be/_files/file/44872003257.pdfIn PDF document text
    • http://hurtowniagrafit.pl/userfiles/file/loserokakogovediligudotop.pdfIn PDF document text
    • https://pkbae.rs/files/degadudimoromiku.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16155b5572cfcc---83472771735.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021092109360897.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161406bd15b9ae---87024192882.pdfIn PDF document text
    • https://argekaucuk.com/nbg/upload/files/23843463559.pdfIn PDF document text
    • http://www.hz-kontejnery.cz/ckfinder/userfiles/files/sajabutodameditivuwoxena.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/tgwjJlsMqHc/uplcv?utm_term=how+to+get+clothes+not+to+shrinkPDF 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_off0000d4c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4C8 10516 bytes
SHA-256: 2a9a7ab9d2e5776b58a3c5a34a245f76f78cc0b2aeb18fd5fb6c32cbf51c59c1
font_01_sfnt_off0000ecab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECAB 18252 bytes
SHA-256: d4c918ec42b0fb362b5e2060d63be97d5861b7d07a33247178b41bb0e1a371cb
font_02_sfnt_off00011be0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1