Malicious PDF — malware analysis report

Static analysis result for SHA-256 f41b9b1ef356f87c…

MALICIOUS

PDF

95.0 KB Created: 2021-09-16 00:28:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d870821bee579c98581d0749b9e8596f SHA-1: 5a03f9d080f3f49039ec1e1f57ab5d4a74f2489f SHA-256: f41b9b1ef356f87c976a008baf87d5aa0f505e8b9b216ff1ee9aeeab612b60a8
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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 https://ketchas.ru/uplcv?utm_term=beyond+the+mountains+and+hills+2016+full+movie+online+free PDF link annotation
    • http://levotst.com/uploads/files/10178891170.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9eb1d80c3---3088576168.pdfIn PDF document text
    • http://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210906_62BC4EA8FD60E9B6.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/94937493565.pdfIn PDF document text
    • https://helices-evra.com/userfiles/file/kosasonanatemodinubepito.pdfIn PDF document text
    • https://12shio3.com/contents/files/9681999528.pdfIn PDF document text
    • https://seo-methodes.com/userfiles/file/pusorikiramutile.pdfIn PDF document text
    • http://simp-q.ru/userfiles/file/35983340205.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141a28f487c5---82475872377.pdfIn PDF document text
    • http://bippex.com/filespath/files/20210902060441.pdfIn PDF document text
    • http://vicc.huh.hu/UserFiles/File/79825117229.pdfIn PDF document text
    • http://topup-fight.com/ckfinder/userfiles/files/nesep.pdfIn PDF document text
    • http://mrukseo.pl/userfiles/file/fasufigudivimoxu.pdfIn PDF document text
    • http://someteme.com/archivos/_20210915195720.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/161341a87b6890---jikapupovogawodanigewi.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/161378f4af2822---38663746582.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/rulanijilekafoxukoriki.pdfIn PDF document text
    • http://teresachild.com/upload/files/30152172715.pdfIn PDF document text
    • https://etevent.itweald.com/uploads/files/61404ab5cfe5d.pdfIn PDF document text
    • http://dietgame.net/admin/fckeditor/data/file/20210905162508.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16137547ddbfb4---61923820042.pdfIn PDF document text
    • http://ambulanceservice.pl/userfiles/file/67662937488.pdfIn PDF document text
    • http://imobiliariaimperio.com/files/files/kipukibabope.pdfIn PDF document text
    • http://noithatphathuy.com/Images_upload/files/84438296897.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_off000108ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000120c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120C3 11412 bytes
SHA-256: 177879ccd231c9356132d9236a4437471f6eb7a571c56cff413e1410c3c0c8b4
font_02_sfnt_off00013ba1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BA1 19356 bytes
SHA-256: 43da5c8a1113fe7f8a52441e5fb6c7604aa63feefdc01b4f0f38c6fc53ba7e93