Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8ba5dae65025b71…

MALICIOUS

PDF

70.5 KB Created: 2021-09-25 15:06:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0077a1ccd10c1f1dab629f1e8bc7f83e SHA-1: e823f7c4f4515e3bda816b7499edde24136ee0aa SHA-256: f8ba5dae65025b712d2b668e0bb2a461141ff39a87164a1dc4cd0e13e5098edf
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many pointing to disposable domains, and exhibits characteristics of a link farm. The primary attack pattern involves directing users to external PDF files hosted on these domains, likely for phishing or SEO spam purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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://edallyshop.com/upload/files/nefaf.pdf In PDF document text
    • http://pusheng168.com/uploadfiles/20210906002539.pdfIn PDF document text
    • http://rayhovietnam.vn/upload/files/degevikugufa.pdfIn PDF document text
    • http://citygclub.com/ckupload/files/17171050302.pdfIn PDF document text
    • https://vinasimex.com/uploads/file/pigasoziragaf.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/5077500439.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161471a793fd6a---vamekaxupozilaz.pdfIn PDF document text
    • http://xn--12cm8caae5d9a0a0a1dxk6dd.com/user_img/files/piwuwejewerejafopuseduraj.pdfIn PDF document text
    • https://seger.cz/userfiles/file/98050950100.pdfIn PDF document text
    • http://handlpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/60890398412.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/kofan.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146240adf448---65441352694.pdfIn PDF document text
    • https://onecre.com/images/content/files/sebagoz.pdfIn PDF document text
    • http://aaas.handyfriendship.com/upload/files/jibolekeb.pdfIn PDF document text
    • http://salonrowerowy.com/userfiles/file/naweg.pdfIn PDF document text
    • http://mixline.ru/img/lib/file/zugufaponigeliw.pdfIn PDF document text
    • http://robertfeinberglaw.com/images/edit_images/file/55574411343.pdfIn PDF document text
    • http://euskararenginkana.eus/files/galeria/files/70384016012.pdfIn PDF document text
    • http://zagazzo.com/userfiles/file/godetidodililomap.pdfIn PDF document text
    • https://esofagopisa.it/userfiles/file/gozivoval.pdfIn PDF document text
    • https://blueparadise.pl/userfiles/file/denug.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/wutajame.pdfIn PDF document text
    • http://mdtrend.hu/files/file/xuzutedovepibe.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161450f2cb0d9a---57425244351.pdfIn PDF document text
    • http://contactfm.be/userfiles/files/delesaxevopefojupekijit.pdfIn PDF document text
    • https://nhahangthanghuong.com/uploads/files/wekatafixepawisuvakotenaz.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/xowepafafudozam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=y+words+to+describe+somethingPDF 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_off0000b585.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB585 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD97 15044 bytes
SHA-256: c7b87b3a7c0f256a5ae5176f7dfe9430873b32d30d31a60ca3c2107f9604f37e
font_02_sfnt_off0000f3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AF 10816 bytes
SHA-256: b86a1bc65236b42c49fb90fbd52b7d41f589ce09e6e0e35ba00c09586be356ca