Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c85b03a8d46b708…

MALICIOUS

PDF

81.9 KB Created: 2021-10-05 00:28:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 00772a6d749d210040e0668a99f6efbe SHA-1: a6d585af41d2f7d24cac7248a37ddfa074b9846a SHA-256: 4c85b03a8d46b708e61d5c0f62b6fb90fac036826cc37e9d892a5400f1d61d94
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to suspicious domains and appear to be part of a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of hosting multiple PDFs on disposable domains, suggesting a phishing or malware distribution scheme. No scripts were extracted, but the presence of external URIs and the overall structure strongly suggest a phishing or malware delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://crewmak.ru/uplcv?utm_term=topics+for+business+report+writing PDF link annotation
    • http://lechioutdoor.com/userfiles/file/sejakoje.pdfIn PDF document text
    • http://pogologistics.com/ckfinder/userfiles/files/zolepube.pdfIn PDF document text
    • http://pharmabiosolutions.com/filespath/files/20210923112135.pdfIn PDF document text
    • http://tinavaron.com/ckfinder/userfiles/files/68070166024.pdfIn PDF document text
    • http://andreuma.madteam.net/ckfinder/userfiles/files/bifujupasofadulesezedim.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/23809661135.pdfIn PDF document text
    • https://kawanmto.net/contents/files/83896687172.pdfIn PDF document text
    • http://philboyd.com/fitafodomaxunubu.pdfIn PDF document text
    • https://ibextrail.com/editor-images/telobasatuvusirevobag.pdfIn PDF document text
    • https://netiko.fr/img/Data/file/90306000313.pdfIn PDF document text
    • https://altsovmun.ru/userfiles/file/59879776394.pdfIn PDF document text
    • http://www.ochoadentalcare.com/tacgestorcontenidos_ochoa/documentos/file/In PDF document text
    • http://herve-coiffure.ci/files/94492299960.pdfIn PDF document text
    • http://www.forteks.com.br/admin/ckeditor/ckfinder/userfiles/Images/73035573101.pdfIn PDF document text
    • http://bamboomfi.com/htdocs/cljr/data/files/fokife.pdfIn PDF document text
    • https://dehayemek.net/upload/ckfinder/files/fitaviletojenedejavuzuvor.pdfIn PDF document text
    • http://synergyproperty.com/images/files/gadaduvugodov.pdfIn PDF document text
    • https://www.utn.ac.cr/sites/default/files/files/kawajudanewifili.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158e43639955---tilapifadozemu.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/49205460910.pdfIn PDF document text
    • http://keralastatetailorsassociation.com/userfiles/file/fagunofibilosikifilu.pdfIn PDF document text
    • https://himalayanespresso.com/espresso_ckfinder/userfiles/files/84121545362.pdfIn PDF document text
    • http://romanasulcikova.cz/userfiles/86730055349.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_off0000d6b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6B3 18872 bytes
SHA-256: 673d85d585a319710b1405ec845fee6424e1748dfa8eb347ddeb3de96237fe95
font_01_sfnt_off0001089f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1089F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000120b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120B6 10736 bytes
SHA-256: d6c06dd0cedbf56cc00bf7a7eb8e73c482a79f8e504750cd2d0764e768f4044d