Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8c27dd247d23375…

MALICIOUS

PDF

76.8 KB Created: 2021-09-01 08:19:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: fdd12a65246ef8fed82d08fc1210882e SHA-1: 1b07fc105a8923cb4c7f78d7f6a5d2507ae30b76 SHA-256: e8c27dd247d233756fa8f3ef4e72ba6d371aebee1d9448b611c67816c574dc2f
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress upload directories, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple distinct hosts and the use of 'utm_term' parameters in some URLs suggest an attempt to obscure the true destination and potentially leverage SEO for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16073173becb4b---fuwuvufox.pdf In PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d23b0ac9039---pevovisamujodakuvudoxilo.pdfIn PDF document text
    • http://daimarconstrucciones.com/images/admin/file/gudiwanekil.pdfIn PDF document text
    • http://gildiamasterov.ru/userfiles/file/danitilobudinalokeguz.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16091829ea9514---dupiwulomepewatax.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd8c4957c11---67768434441.pdfIn PDF document text
    • https://gallerylingard.com/uploads/file/72780032572.pdfIn PDF document text
    • http://energo-winstal.pl/userfiles/file/11983445100.pdfIn PDF document text
    • http://webinaris.training/ckfinder/userfiles/publics/files/29830085527.pdfIn PDF document text
    • https://swagath.co/new/ckfinder/userfiles/files/gegufemobebasijujukowane.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/da63816f69ab80d566e2154656ac26bd/57731012936.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa6490aa44e---papirozuw.pdfIn PDF document text
    • http://petukmahaaaraj.com/userfiles/file/67843551786.pdfIn PDF document text
    • http://daimarconstrucciones.com/images/admin/file/19298622711.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210618091119.pdfIn PDF document text
    • https://priscar.com/documents/files/23147549980.pdfIn PDF document text
    • https://arrad.ch/modules/ck/ckfinder/userfiles/files/32917434522.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dfc86894ea---52090484503.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/ebc07f83bf70314ffde952cb85b4ee26/zuvosometogarek.pdfIn PDF document text
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/jebipadozote.pdfIn PDF document text
    • http://dienlanhlongan.com/upload/files/vabogo.pdfIn PDF document text
    • http://bannermaul.com/userData/board/file/9836609116.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160be086e4cfb0---70849127363.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad05de8e911---8711948250.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=what+are+the+six+pairs+of+corresponding+congruent+partsPDF 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_off0000c976.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC976 16248 bytes
SHA-256: bf20d36d57c6ec259e49b83d14590044df10e57b5e372e2ab8d5d79bc1148509
font_01_sfnt_off0000f353.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF353 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010b6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B6A 11048 bytes
SHA-256: a8d62fbed955cc5f8656c173689d4f132cd3deed7733c7fb218577608e1afea9