Malicious PDF — malware analysis report

Static analysis result for SHA-256 13d66afa3834dcab…

MALICIOUS

PDF

78.2 KB Created: 2021-09-08 13:51:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: dd57c57528adfd0e5bdbb4f61e50c0e1 SHA-1: 240ed9bc22e1eee3da58b02b87a8fbfa154c5919 SHA-256: 13d66afa3834dcabfc0d844bb0be597a968307d1f46f329c088f669b24d55753
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many pointing to disposable domains, and one specific URL is identified as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document's purpose is to host many links on potentially untrusted domains. While no scripts were explicitly extracted, the presence of PDF-specific heuristics and the nature of the URLs suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=wta+rankings+2018+pdf PDF link annotation
    • http://fotosvatba.net/userfiles/file/99879044823.pdfIn PDF document text
    • https://tspinstruments.com/cache/fck_files/file/wipikizutazesisiliro.pdfIn PDF document text
    • http://www.louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/tofonoduxukidamarefegibot.pdfIn PDF document text
    • http://custom-mugs-factory.com/uploadfile/files/domikilexeberewixem.pdfIn PDF document text
    • http://gccde.com/downloads/blog/geust/files/wenuk.pdfIn PDF document text
    • http://kssi.ir/public/userfiles/file/42113882952.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/kelibada.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/vevaxawo.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/nomuxupanutugeziduko.pdfIn PDF document text
    • http://hoanggiaphatstone.com/upload/files/pikefupekiwibolisaguxiron.pdfIn PDF document text
    • http://rbc-bezorgdiensten.nl/upload/28748304561.pdfIn PDF document text
    • http://trevorhannant.com/57704559734.pdfIn PDF document text
    • http://wsm.hk/images/files/56042580165.pdfIn PDF document text
    • http://jumpinfit.it/userfiles/files/likudexoxiwonelopiximus.pdfIn PDF document text
    • http://truhlarstvi-strakonice.cz/files/file/xezitebusuxoganimabujejo.pdfIn PDF document text
    • http://skulpt.in/admin/uploads/file/runojojumunisiwitizukuv.pdfIn PDF document text
    • http://grandwatergatehotel.com/upfile_hotel/files/53977139932.pdfIn PDF document text
    • http://yenidenyuzlendirme.com/ckfinder/userfiles/files/dafudebarizijusu.pdfIn PDF document text
    • http://sarkar.ie/userfiles/file/32472217626.pdfIn PDF document text
    • http://opakowania-loga.pl/zdjecia/fotki/file/23315704729.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136c90eedcc0---70622312751.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/62809478976.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/8eac6b4996b7ed69df3ca4b9cc07f14d/vekutoju.pdfIn PDF document text
    • http://labellebeaute.com.hk/ckfinder/userfiles/files/lugoxofitobir.pdfIn PDF document text
    • http://aodaiminhhanh.com/app/webroot/uploads/files/leredojegivegavorexifuzov.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_off0000c555.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC555 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD6C 10964 bytes
SHA-256: a69ee286b0398ce1a648684331a0a9c15bba714a0ef4cd17bee15cb017c9a922
font_02_sfnt_off0000f6dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6DD 19856 bytes
SHA-256: 14cebfe4854b920f9b01d4dfdaeacca09e2c7c36982d56c75b165992f8190539