Malicious PDF — malware analysis report

Static analysis result for SHA-256 23641832beb150be…

MALICIOUS

PDF

76.9 KB Created: 2021-10-04 15:54:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 66f45ef97c4b121f1efa82bbaa240309 SHA-1: 23621f39563eaf7c697db07ce7c0897ffabd895a SHA-256: 23641832beb150be1db2512996d46feb6ce561f73ea532b06875367b62237927
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the nature of the embedded URLs and the heuristic firings strongly indicate a phishing or malware distribution attempt, likely initiated via spearphishing.

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 https://philabc.ru/uplcv?utm_term=horticulture+quiz+and+answers PDF link annotation
    • https://maria-galland.ru/files/file/59291147184.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/34673824269.pdfIn PDF document text
    • https://architektor.ru/uploads/file/libukaxafovefegiv.pdfIn PDF document text
    • http://gamax-motor.cz/data/dokumenty/pifuxiv.pdfIn PDF document text
    • http://arrhythmiaclinic.com/userfiles/file/20210923155641.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/files/files/54321940460.pdfIn PDF document text
    • http://angel-conference.org/upload_fck/file/2021-9-5/20210905213701916986.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16143470f6bebd---3604969481.pdfIn PDF document text
    • http://sergeisurzhin.ru/ckfinder/userfiles/files/fuvebizarubuz.pdfIn PDF document text
    • https://krygina40.ru/UserFiles/File/zutekoxigum.pdfIn PDF document text
    • http://www.rannatennis.ee/data/upfiles/files/fexanitimaba.pdfIn PDF document text
    • http://tropo-design.com/ckfinder/userfiles/files/72616433477.pdfIn PDF document text
    • http://studioferrato.it/userfiles/files/63293761831.pdfIn PDF document text
    • http://arucax.am/user_images/file/latopo.pdfIn PDF document text
    • http://gangwonbnb.com/FileData/ckfinder/files/20210929_F16EFCB3DC581317.pdfIn PDF document text
    • http://konberdbio.com/upload/files/lavegaguwu.pdfIn PDF document text
    • http://odra.cycling-recycling.eu/imgturysta/files/75016159823.pdfIn PDF document text
    • http://escalierdurire.fr/ckfinder/userfiles/files/95469495618.pdfIn PDF document text
    • http://festacreativita.org/userfiles/file/motakavadajunupaki.pdfIn PDF document text
    • http://cherriestattoo.com/ckfinder/userfiles/files/tonipevadonowo.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bb7e5a7ab5.pdfIn PDF document text
    • http://schuetzenfest-hemeringen.de/ablage/userfiles/files/tifuberoteruxegetakidisu.pdfIn PDF document text
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/tewagujijafetobun.pdfIn PDF document text
    • http://www.siposferenc.hu/html/26758897097.pdfIn PDF document text
    • http://sissonne.hu/editor_up/kukivawir.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_off0000c788.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC788 10748 bytes
SHA-256: 770d8a5e89a1919d143a541805427f99a63e3447638456ae77a1921b82b3daf4
font_01_sfnt_off0000e037.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE037 17688 bytes
SHA-256: 0d99a142b623660bf058f10432e2edbfcd6b674b7394c58291865d6717ea14e1
font_02_sfnt_off00010d7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1