Malicious PDF — malware analysis report

Static analysis result for SHA-256 5ece3ed57d3f599c…

MALICIOUS

PDF

76.2 KB Created: 2021-09-14 02:23:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2c1fcc73d482d5a1216c0d11a7cdbe6b SHA-1: 68d30c567248de3f5f4281f69a733bada26db826 SHA-256: 5ece3ed57d3f599c718379f0155a5d6eca209f9f80def51786fd8029b4f133d0
126 Risk Score

Malware Insights

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

The PDF sample was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV detection, indicating malicious intent. The presence of numerous embedded URLs, many pointing to disposable domains and structured as a link farm, suggests a phishing or malware distribution scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically highlights the nature of these links, reinforcing the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://polimak.pl/userfiles/file/buwafexe.pdf In PDF document text
    • http://studiodebiaggi.eu/userfiles/files/49967645705.pdfIn PDF document text
    • http://news-hk.net/uploadfile/file///kefatofor.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/kudefikipe.pdfIn PDF document text
    • https://drosamahetta.com/userfiles/file/95827889632.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/b71859d3fa33eb5bfb21c2aaf1a980be/kuvamojuporugurinuwo.pdfIn PDF document text
    • http://methese.com/upload/files/fimufobuxifijev.pdfIn PDF document text
    • https://birudongker.com/contents/files/tameletarovawoz.pdfIn PDF document text
    • http://cofetariafraguta.ro/UserFiles/file/78725677671.pdfIn PDF document text
    • http://montagnobozzone.it/userfiles/files/suzokaw.pdfIn PDF document text
    • https://md-bud.pl/szklo/photos/file/75465768631.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee9c1399cb---nakilekigowenomekigopotu.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/10754722741.pdfIn PDF document text
    • https://peoplesmodelinternational.com/ckfinder/userfiles/files/rixinikuzufabewa.pdfIn PDF document text
    • https://foodsafebox.com/ckfinder/userfiles/files/33447679282.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/fewogibipavegej.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/8340635009.pdfIn PDF document text
    • http://fkm-lux.by/var/upload/file/45879586878.pdfIn PDF document text
    • https://rpaxis.net/userfiles/file/folokulusuxasedosokoz.pdfIn PDF document text
    • http://hoangminhphatkorea.com/webroot/img/files/lomekumekagibadedol.pdfIn PDF document text
    • https://byocamacho.com/ckfinder/userfiles/files/lewoz.pdfIn PDF document text
    • http://jhdljz.com/userfiles/file/1631469045.pdfIn PDF document text
    • https://www.passion-rnd.com/upfile/files/2021/09/13/bujipiwipofawisaj.pdfIn PDF document text
    • https://sportnazona.bg/f/uploads/files/tuzevizelurubumiromobu.pdfIn PDF document text
    • http://thebrownbag.vn/upload/files/xokufitagipujebidivepova.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=fatal+fury+apkPDF 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_off0000c28c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC28C 18984 bytes
SHA-256: 178615a2cc4d27c83277ed2277e64c0c9c6e5f34f66a00e5959f57f8c3233513
font_01_sfnt_off0000f4a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010cba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBA 10020 bytes
SHA-256: 7dfef46479b8e9c65890ceb9aa8ee4d9bb5d4073c2597ba305ab3e5ee2a8c589