Malicious PDF — malware analysis report

Static analysis result for SHA-256 8109c5a4c1e0c7cb…

MALICIOUS

PDF

70.5 KB Created: 2021-09-25 02:24:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8dde506327f12a655cf6f5f95f6f4d9f SHA-1: b7c6b3c67c033a307623914e7049a5c35bd725db SHA-256: 8109c5a4c1e0c7cbeeee24f909b6d36948312e267074d2a3b56ef7167949fb1c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm pointing to numerous other PDF files hosted on potentially compromised or disposable domains. Heuristics indicate these are likely part of a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely involving the exploitation of vulnerabilities within the PDF reader to execute a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9825

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://nceed.kr/pds/userfiles/files/keduwanitorageduw.pdf In PDF document text
    • http://dalhousieretreat.com/cote_dor_import/admin/ckfinder/userfiles/files/5118460786.pdfIn PDF document text
    • http://lso-msm.fr/userfiles/file/texebuzazojudesuxo.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/ci097dit44f681lgdjtf3lqupr/wenipetipawela.pdfIn PDF document text
    • http://watch62.ru/files/files/94646583358.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614dd92eec329---kuzojuluwiwuwit.pdfIn PDF document text
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/5256240536.pdfIn PDF document text
    • http://duoctruongxuan.vn/userfiles/image/file/53982741637.pdfIn PDF document text
    • http://creaorganization.com/depo/sayfaresim/file/1872133882.pdfIn PDF document text
    • https://franchisebusinessadvisors.franchisebrokerwebsites.com/broker-site/files/files/84320560306.pdfIn PDF document text
    • http://pujcovnanaradi-tvarozna.cz/userfiles/files/xunilotexetum.pdfIn PDF document text
    • http://blueyee.com/upload/file/191411598944.pdfIn PDF document text
    • http://printrun.nl/userfiles/files/86799504452.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613ccf7e04c89---zasibajinisebolumuvu.pdfIn PDF document text
    • http://www.clc-engineering.com/siteuploads/editorimg/file/8188865401.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614121425df9a---sibivopuno.pdfIn PDF document text
    • http://kimhoatra.vn/upload/fckimagesfile/xebolapovopikovuratekipis.pdfIn PDF document text
    • https://www.sistemkabin.com/ckfinder/userfiles/files/dibedufiral.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/minelat.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/82984817344.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/67714585752.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16141e640a6e03---jafopotigopo.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210909_BD663A82BC2AFC6E.pdfIn PDF document text
    • http://ddaengshop.com/ckupload/files/xejifiditalubonisuv.pdfIn PDF document text
    • http://triatlonbizuterie.cz/sites/default/files/file/gitezusiganotalobuxam.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/80950564463.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/37806212608.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=android+space+between+buttons+in+linearlayoutPDF 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_off0000b360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB360 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB72 15792 bytes
SHA-256: 68ade8720e83d17ab5d47d686d51ce15acc9fa03421e16ade756c5866a19d0e0
font_02_sfnt_off0000f3a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A4 10928 bytes
SHA-256: 066292ee03687b8a0beb0c15d90ee9835a24fdf0d9effd34b186f0247318c57d