Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5b6d2c87f042934…

MALICIOUS

PDF

73.8 KB Created: 2021-09-10 14:25:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 41f8403ca517842b907793365b76a7df SHA-1: e0a5452bc854e1e31166b851d7c2e5433cab5df4 SHA-256: f5b6d2c87f042934db04a1a9b4d45ba7c107208aae92c6a990a2ae0ac00cc7b0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which are structured to appear as file downloads. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a high volume of links on disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or delivering further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cructi.ru/uplcv?utm_term=how+to+transfer+data+to+another+mobile PDF link annotation
    • http://blueleaves.ru/userfiles/file/demovevixel.pdfIn PDF document text
    • http://js-space.de/userfiles/file/wafenunego.pdfIn PDF document text
    • https://drddvichitra.com/userfiles/file/11191603444.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210906_86AF9C0A30778E0E.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/33422003430.pdfIn PDF document text
    • http://www.ecostroyservis.ru/File/88394476585.pdfIn PDF document text
    • http://kingbikeonline.com/images/upload/File/53775036525.pdfIn PDF document text
    • http://aatmicscience.org/asuserfiles/file/93472456365.pdfIn PDF document text
    • http://media-production.net/admin/ckfinder/userfiles/files/datofelonawijinukope.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/161399c896f764---39575132789.pdfIn PDF document text
    • http://bigbazar.cz/is/images/FCKeditor/File/gupugixizominolobepezef.pdfIn PDF document text
    • http://ekvatorbl.com/userfiles/file/xamitinid.pdfIn PDF document text
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/80779555129.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210909114456.pdfIn PDF document text
    • http://asja.ua/userfiles/file/burufawalazizikekuviviw.pdfIn PDF document text
    • http://www.onlinenieuwsbriefversturen.nl/gebruikers/afbeeldingen/zerukujita.pdfIn PDF document text
    • http://bibikid.ru/upload/46513381588.pdfIn PDF document text
    • https://www.tahitotfaluovodak.hu/ckfinder/userfiles/files/91249179592.pdfIn PDF document text
    • http://viquadro.com/userfiles/files/zusaka.pdfIn PDF document text
    • https://mailing.crpm.ch/ck/ckfinder/userfiles/files/dudotirulovapiwix.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a141a00fcd---malapaxuzibomudoseb.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/31717853147.pdfIn PDF document text
    • https://qualityroofinnandsuites.com/nbloom/fckuploads/file/33471086557.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_off0000bcf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCF8 17144 bytes
SHA-256: ed0fcaa707bd7f71639749fcfc8bbefd00a46a289306f7ddc265021dd02b9dfb
font_01_sfnt_off0000e8f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001010c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1010C 10836 bytes
SHA-256: edfcd6c7de0412a3d42d4039869310b6887947313e4644afd7db6e28104a38fd