Malicious PDF — malware analysis report

Static analysis result for SHA-256 c31ba36a5a878852…

MALICIOUS

PDF

85.9 KB Created: 2021-07-31 09:15:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 98ca135ab7bd9576c05233c593daab29 SHA-1: 90d6a2ad5a907f90c3b99ab23aaec98858bb264e SHA-256: c31ba36a5a87885271274d3fbe6116bbd79e1b9aa79998667095fffa4b6c3935
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links pointing to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics indicate an attempt to exploit users through deceptive links, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://pistant.ru/uplcv?utm_term=tabla+distribuci%C3%B3n+normal+estandarizada+z PDF link annotation
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/2bb4ded259152b5bee590870909a3316/nelotogawapesud.pdfIn PDF document text
    • https://mides.vn/images/ckeditor/files/41622646844.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/a2871f348dadc590d0e393a063fe2530/pekevulelabewovi.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2e2b33d4ad---89907982869.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b60f7f2a430---22186318727.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f34092d5cd---72143080768.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce747d9a03---minilakepovidumepex.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/160987e1a30b3c---wajipo.pdfIn PDF document text
    • http://myblindz.com/fck_user_files/file/widamabilafevobineta.pdfIn PDF document text
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/79204de553757d26010056f465c1652b/16438172460.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/29edc3e9247820e51fddd02242d5a43a/68203159829.pdfIn PDF document text
    • http://artecgroupservices.com/imagenes/file/sububotoxuwodimijul.pdfIn PDF document text
    • http://asbufestival.com/uploads/FCK_files/file/62131443870.pdfIn PDF document text
    • http://robedecreateur.com/img/files/64049028594.pdfIn PDF document text
    • http://ledseoul.com/userData/board/file/44968652532.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/12457861939.pdfIn PDF document text
    • https://centrosteadycam.it/wp-content/plugins/super-forms/uploads/php/files/edc95530fe62631af2fae436cc5e25a8/pibebib.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160786d73a813a---16104494248.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/e2fe5773cefa6c537a589ae82bd3f72a/gemevoxejiba.pdfIn PDF document text
    • http://cjatkinson.com/userimages/86089637081.pdfIn PDF document text
    • http://gdbchurch.com/clients/43262/File/32682455713.pdfIn PDF document text
    • http://dajuicebarus.com/uploads/files/69436371983.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/letizatikosipezimusesubax.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_off0000e5cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fddd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDDD 18636 bytes
SHA-256: 032779203fef850c72f7e91f902d7a48cc8cdd9cb71ca7e58c89bc0563ce657b
font_02_sfnt_off00012db5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DB5 10932 bytes
SHA-256: ca1c74438246d9e9bbda873c51069c83004581b1b9f3a8ef6cfddb0e3f7fab54