Malicious PDF — malware analysis report

Static analysis result for SHA-256 139539f856182724…

MALICIOUS

PDF

75.8 KB Created: 2021-09-01 06:56:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 48319aa91b77cc17c1ac8eff11381f83 SHA-1: 7b02e70cf39af01c469c848b2189aba281576352 SHA-256: 139539f856182724454feadb60e1ab175a3a3d1f9a8f2821014a4294787401cb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, containing numerous URLs pointing to potentially compromised websites or disposable hosting. The presence of these links suggests an intent to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=business+administration+courses+pdf PDF link annotation
    • http://bsp-oblspl.org/ckfinder/userfiles/files/bosoj.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071a78ecebe2---83105215119.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bf1a0f4d365---56381751203.pdfIn PDF document text
    • https://digireg.nz/upload/99683083105.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/81bbfde83b92edd4fe308eb4b4bdf6b3/wupanelo.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/bed15dc2a044b29ec916c4fd630ca34c/40528460284.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/79701852470.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/nimanosibizop.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/82bg6cibbinp2092bknv22ilsh/6018282127.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/njocglm6k2nncudl6mffa08n71/duruxuwaxibapur.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202106301816289376.pdfIn PDF document text
    • https://facades-et-traditions.com/actualites/file/dusepejeguwokawazo.pdfIn PDF document text
    • https://red-adlay.com/upload/files/sidir.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078c626236eb---lusudenog.pdfIn PDF document text
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/c0fe98cdc30782fcea44b400a4a9a060/99515352841.pdfIn PDF document text
    • http://creativeindustries.ru/uploads/userfiles/file/wuwidajisaza.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/5272680545.pdfIn PDF document text
    • http://kompletucetnictvi.cz/files/file/bupoke.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_off0000c5f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5F6 16620 bytes
SHA-256: c9ff8b906246f597c22d8099773e569b5c38b79762233c94eb4383d29e447528
font_01_sfnt_off0000f0aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000108c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108C1 10888 bytes
SHA-256: 6b4c5aa70d668ead372d0823b7546c5f895a513ca4ea66c774262ad9ebdec3b9