Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e37cb9af41e7729…

MALICIOUS

PDF

75.0 KB Created: 2021-09-12 22:00:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ea85e0ffdeb457017d622ad8a0af8c18 SHA-1: b5e29549c5c7462afa4ef47f82f95a693fff3a84 SHA-256: 4e37cb9af41e77296f09f6f6179f884abf7067c913c9d4ad449796c82e4956b0
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with many URLs pointing to compromised WordPress upload directories and disposable hosting. These findings suggest the document is designed to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba882f2c86---78375909842.pdf In PDF document text
    • http://nhatrangpalacehotel.com/app/webroot/upload/files/fupotejotavikejewe.pdfIn PDF document text
    • https://ekselantechnology.solutions/ckfinder/userfiles/files/minenopugeratagefi.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/24128436048.pdfIn PDF document text
    • https://yar-net.ru/userfiles/file/gilexabatigora.pdfIn PDF document text
    • https://searchkar.com/ci/userfiles/files/mivupakulezu.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/28609445129.pdfIn PDF document text
    • http://thesciencenetwork.org/uploads/files/sofila.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/16130322f61974---38915978153.pdfIn PDF document text
    • http://cokhivietuc.webthoidai.com/img-vietuc/files/40920201686.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130922d2cd24---1082620240.pdfIn PDF document text
    • http://eluvial.com/sites/all/sites/eluvial.com/files/11985050448.pdfIn PDF document text
    • https://matao.ro/app/webroot/files/userfiles/files/madanajunavazuxadinipag.pdfIn PDF document text
    • http://thietbiotoviet.com/Images_upload/files/mafawusopikitazowuzute.pdfIn PDF document text
    • https://cortemadera.com/wysiwygfiles/file/39894865738.pdfIn PDF document text
    • http://www.offshoreyachts.net/web_upload/editor/files/baxokin.pdfIn PDF document text
    • https://sinaia-vik.com/admin/fckeditor/editor/filemanager/connectors/php/file/29719124890.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16135e4370a212---wuzotakojatolebopivoraz.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/18296695890.pdfIn PDF document text
    • http://pcwenhua.com/uploadimg/file/1630809177963262803.pdfIn PDF document text
    • http://locthanhroyal.com/upload/files/jijekupevofokukujupam.pdfIn PDF document text
    • http://cosmoscm.com/contents/files/12996541275.pdfIn PDF document text
    • https://amoslodge10-org.alljobsinliberia.com/ckfinder/userfiles/files/4244286772.pdfIn PDF document text
    • http://hitmet.slektenkaas.com/bilder/file/daxatup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+insert+a+video+in+pdfPDF 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_off0000c38d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC38D 16604 bytes
SHA-256: 8440874cac03bfb59eb93c3d094a016f78f463449996d7f356cf9da8ab624478
font_01_sfnt_off0000ee62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE62 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010679.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10679 10588 bytes
SHA-256: b797b0f6a0079e629901f44af75732712a61a54cfdf1b0ef5cdb857b63905875