Malicious PDF — malware analysis report

Static analysis result for SHA-256 ea63bb16c23c3ba9…

MALICIOUS

PDF

89.3 KB Created: 2021-10-05 16:03:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 61b24d2e544981340a41010b4947b746 SHA-1: e85d621e94f7ba204a1517f7a17702213f54f482 SHA-256: ea63bb16c23c3ba991976fb70fc9fb374b972d96deec06c12f94396bb3dfdf90
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs that form a link farm, pointing to various domains, some of which are hosted on compromised CMS upload storage. The primary function appears to be directing users to potentially malicious websites, likely for phishing or malware delivery. No scripts were extracted, but the PDF structure itself facilitates the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://medvor.ru/uplcv?utm_term=1+cups+flour+in+grams PDF link annotation
    • http://homespakistan.net/magzine/uploadfiles/file/tajolove.pdfIn PDF document text
    • http://arniuniversity.in/ci/userfiles/files/81572979425.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/fonodiwitav.pdfIn PDF document text
    • https://niagarablock.com/application/webroot/userfiles/file/rexebomaveradigelo.pdfIn PDF document text
    • https://easternresources.net/ckfinder/userfiles/files/pulesegujisepalaru.pdfIn PDF document text
    • https://mvmdigital.gr/files/files/34516128943.pdfIn PDF document text
    • http://kronospan-mofa-hungary.hu/editor_up/1216337816.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd5dde7899---88095785779.pdfIn PDF document text
    • http://agriturismolataggiasca.eu/userfiles/files/43913845903.pdfIn PDF document text
    • https://booburger.myagenda.cz/pictures/editor/files/80996157862.pdfIn PDF document text
    • http://kroonzuivel.nl/ckfinder/userfiles/files/90312700455.pdfIn PDF document text
    • http://shendaoguoji.com/data/attachment/file/fotipudobed.pdfIn PDF document text
    • http://divyabodhanam.org/userfiles/file/kobolil.pdfIn PDF document text
    • https://energooptima.hu/upload/File/47474449480.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aba56f415b---firukubuneg.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/68590264067.pdfIn PDF document text
    • http://fthyhs.com/resource/docContentImg/file/2021-09-11/912f62bc975b46c2322021abffe0336e.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/hjaiudtnl96tvk16vgme599dt5/21650311434.pdfIn PDF document text
    • http://germainelecocq.it/userfiles/files/walukaduzonoxosexepude.pdfIn PDF document text
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/potebifemebadudixaze.pdfIn PDF document text
    • https://biserica-izvorul-tamaduirii.ro/files/78978700100.pdfIn PDF document text
    • https://advantage.ee/media/contents/file/fokusizalojib.pdfIn PDF document text
    • https://astoraccessories.com/uploads/ckfinder/files/9521415611.pdfIn PDF document text
    • http://cdmvt.cz/sites/default/files/30150411300.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/e8g09vm0cu28aklbk6btlr2k5j/4883814398.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_off0000f0be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0BE 10648 bytes
SHA-256: 95bde1b0f22543b973ac248d5e6aecc4731acb0097690a8faef429f2b04cf697
font_01_sfnt_off00010912.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10912 21092 bytes
SHA-256: 285553fd3f188991f458ecb6570c93b7e729a8846d351b9d87919285a82750ee
font_02_sfnt_off00013f7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F7F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1