Malicious PDF — malware analysis report

Static analysis result for SHA-256 12c77a83f80671f0…

MALICIOUS

PDF

81.3 KB Created: 2021-09-19 11:17:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2f25e5bfadbf97b8c6f3e500bfda6398 SHA-1: f0432bb4ddfc0bc70c6c4c26bec7122486e3f350 SHA-256: 12c77a83f80671f0d130b9f21a1cf066703147333bfa3ab06a038aa2002a8db1
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs, many pointing to disposable hosting, suggesting a link farm designed to trick users into downloading further malware. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a deceptive workflow.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://pistant.ru/uplcv?utm_term=std+10+ss+textbook+pdf PDF link annotation
    • https://hankilfood.com/userfiles/file/20210906223520.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/futegozato.pdfIn PDF document text
    • http://xycrusher.com/d/files/7884394685.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/48031857823.pdfIn PDF document text
    • http://kasand.com/userfiles/kavojit.pdfIn PDF document text
    • https://bcm.es/files/galeria/files/nilamekozodukaregafuk.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/161365444b7f7f---58693894803.pdfIn PDF document text
    • http://4chan.ro/UserFiles/file/punalewefajedoxuwawe.pdfIn PDF document text
    • http://teplolux72.ru/upload/file/jakotumuwafexazuxexojer.pdfIn PDF document text
    • http://chemsdano.com/upload/files/nuvafuxuw.pdfIn PDF document text
    • http://schroniskoorzechowce.pl/ckfinder/userfiles/files/miwoziliwikozulav.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/soxopupisuzak.pdfIn PDF document text
    • http://katachizu.com/img/news/files/32765944503.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613fac1e0f2e0---24366672564.pdfIn PDF document text
    • http://ulleungroadtour.com/FileData/ckfinder/files/20210908_EFE92BECB24E83B2.pdfIn PDF document text
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/luxefewe.pdfIn PDF document text
    • http://indcms.testingmachines.com/images/file/selamuwemesa.pdfIn PDF document text
    • https://kattliv.com/kattliv/admin/userfiles/file/tukaji.pdfIn PDF document text
    • http://okcashbagusa.com/uploads/files/62537330215.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/36569710171.pdfIn PDF document text
    • http://jfe.hk/userfiles/dobaranewak.pdfIn PDF document text
    • https://darshanam.com/ckfinder/userfiles/files/50111486921.pdfIn PDF document text
    • http://eastcoastbiker.de/sites/default/files/file/69516794856.pdfIn PDF document text
    • http://flynewsletter.com/uploads/file/31104717407.pdfIn PDF document text
    • http://lotusburbank.com/uploads/files/sokiguruvuviregufi.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_off0000d895.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD895 10568 bytes
SHA-256: fe2790b6d58809567b7842326792c2bd1f6a852fbea64ced638d0b42ae2dda46
font_01_sfnt_off0000f0a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A6 18180 bytes
SHA-256: f6b0024f055f6ba66fbd7082d9403a9a2f2d4c12553c73fbcdf3967f3ea4d9bb
font_02_sfnt_off00012005.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12005 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1