Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcb53987e7190659…

MALICIOUS

PDF

69.0 KB Created: 2021-09-28 19:37:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2fa115db68430ed08f98765c0623085e SHA-1: 3f29a6f85725b2d7644670b6a04380444dba6201 SHA-256: bcb53987e71906591c83f0fff8c66abdc36b8581d878886c804c2c0c65901882
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with a high heuristic firing indicating it's a link farm on disposable hosting. One URL, 'http://strandedtattoo.info/file/makekimiwe.pdf', is particularly suspicious. While no scripts were directly extracted, the PDF structure and the presence of many external links suggest an attempt to redirect users to potentially malicious content or for SEO poisoning. The ML classifier also flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 4

  • 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://strandedtattoo.info/file/makekimiwe.pdf In PDF document text
    • http://usa-ex.com/images/blog/file/77967567530.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/bobaviwogoxaxawizewidasok.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/49469112684.pdfIn PDF document text
    • https://walnutcreekguide.com/wysiwygfiles/file/vawiviw.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16140d53f34c6c---69873306938.pdfIn PDF document text
    • https://otterdisplay.com/userfiles/file/rotemovikigitelodubed.pdfIn PDF document text
    • http://travelsi.ru/ckfinder/userfiles/files/xogarabefawewisimefomapaj.pdfIn PDF document text
    • http://gianenricofabro.com/userfiles/files/pixexuziviwofesanam.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/ruvedefotekomus.pdfIn PDF document text
    • http://patroha.hu/file/50799012577.pdfIn PDF document text
    • https://turkihale.com/userfiles/file/In PDF document text
    • https://mcdelandes.ca/uploads/file/numexomiba.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613f65377be77---53093957799.pdfIn PDF document text
    • http://recviem.ru/img/upload/revuzor.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/favegexobu.pdfIn PDF document text
    • http://rrarental.org/upload/file/mamupomorokerimileme.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/guxunidiwo.pdfIn PDF document text
    • http://melly-incendie.fr/img_db/guwel.pdfIn PDF document text
    • https://towa-aaa.jp/userfiles/file/wadiwumesupinexet.pdfIn PDF document text
    • https://idosekotthonaveresegyhaz.hu/files/files/20912929618.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/5472679717.pdfIn PDF document text
    • https://efckrakow.pl/userfiles/file/63828508095.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/54172421926.pdfIn PDF document text
    • https://mauspro.net/upload/files/selotud.pdfIn PDF document text
    • http://lgassociates.in/uploads/73656845071.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=enregistreur+de+frappe+android+gratuitPDF 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_off0000b015.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB015 10712 bytes
SHA-256: a6a34d5b78b549b42bb6c495314945ff676860bfc0ba3391f1a1b3ab9342a2c0
font_01_sfnt_off0000c889.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC889 15224 bytes
SHA-256: 45ccec15fbfd19fe823994300a1b4b1c1c77e575a4685fa3477f164ebc1d8279
font_02_sfnt_off0000ee9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1