Malicious PDF — malware analysis report

Static analysis result for SHA-256 824330ecdbdf4cc5…

MALICIOUS

PDF

70.6 KB Created: 2021-09-24 22:29:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7cb02139855ec4e3d1f3a72ebceefd20 SHA-1: e805a2eb7558f458696bf684bd53ad09c6acee16 SHA-256: 824330ecdbdf4cc53b0cdc445efc7c4c77c691cc56dd90fe4ab50848c9a51776
96 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports the conclusion that this document is intended to lead users to malicious or unwanted content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 5

  • 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 https://coretry.ru/uplcv?utm_term=minecraft+for+free+ios+2021 PDF link annotation
    • https://mylin.in/ckeditor/ckfinder/userfiles/files/lumej.pdfIn PDF document text
    • http://cke.hk/userfiles/pididadevadilikatezuluri.pdfIn PDF document text
    • https://dangeloremodeling.com/nbloom/fckuploads/file/vedoxosi.pdfIn PDF document text
    • http://hiniceshine.com/upload/14888363423.pdfIn PDF document text
    • http://baltic-rt.ru/ckfinder/userfiles/files/83038046850.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614209063e773---vilasilunifu.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/bixudugepepifej.pdfIn PDF document text
    • http://dsfly.com/uploads/files/wewadapotusixonazinaseke.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/161307bbb8e3d7---jirebe.pdfIn PDF document text
    • https://its-bulgaria.bg/files/file/gagizutop.pdfIn PDF document text
    • https://smshealthcareservices.com/ckfinder/userfiles/files/11924755997.pdfIn PDF document text
    • http://yanarfabrics.com/firma/files/64565006496.pdfIn PDF document text
    • https://ancoraeducacion.com/images/xilubupowojiwowu.pdfIn PDF document text
    • http://czechdidgeridoo.com/admin/upload/file/golujidimugoxapi.pdfIn PDF document text
    • http://ketex.com/trcgp/ckfinder/userfiles/files/jelatoxuzevub.pdfIn PDF document text
    • http://saeronbio.com/userData/board/file/tomokafanawofa.pdfIn PDF document text
    • http://app0.linkeo.it/ckfinder/userfiles/files/pumugatawutezuza.pdfIn PDF document text
    • http://stmrcstvm.com/userfiles/file/60769190936.pdfIn PDF document text
    • http://blossomtour.net/FileData/ckfinder/files/20210908_3B46D0880F3AA55B.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202109140452187057.pdfIn PDF document text
    • https://bakwanudang.com/contents/files/59585842653.pdfIn PDF document text
    • http://sitarofindiamd.com/userfiles/file/tolav.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/d0d43c7977e01b91692d376a95ac96d5/gogiko.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/jopegilumolagidurosixejew.pdfIn PDF document text
    • http://zabbeleecooking.com/ckfinder/userfiles/files/jamowezememu.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/patoroluwepaf.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_off0000b47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB47A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC8C 15736 bytes
SHA-256: 23ca372c97b809c1f8fa13e6653966b527fad62120948456d8ec972f98a093fd
font_02_sfnt_off0000f405.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF405 10572 bytes
SHA-256: d46cc1929fd0ed4d972865efddd765ba6a054fa57bd990d8bb8199faa61247e4