Malicious PDF — malware analysis report

Static analysis result for SHA-256 83425fc9f080efea…

MALICIOUS

PDF

70.2 KB Created: 2021-09-28 09:11:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 68220aef6d9383409bd408d0b8cc618f SHA-1: 3419192dcc5ee9a8ee126d361df6970c5ca78a1e SHA-256: 83425fc9f080efea1111f022b33ff1046ddb468dfba8df85ebdac0b93c127245
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs pointing to a link farm, suggesting a phishing or SEO manipulation scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a high number of distinct hosts and links, reinforcing the link farm hypothesis. No scripts were extracted, but the presence of many external links suggests a potential for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://web-news.eu/www/pkpar/userfiles/file/xolutelazi.pdf In PDF document text
    • https://himalayanespresso.com/espresso_ckfinder/userfiles/files/76274952579.pdfIn PDF document text
    • https://nawaasha.org/userfiles/file/96966640981.pdfIn PDF document text
    • https://atiksigorta.com/files/gugizarojovo.pdfIn PDF document text
    • http://kiddeefire.com/media/userfiles/files/gubikapixosalebik.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614b439a8147f---zurujemuselixaj.pdfIn PDF document text
    • https://eldorado777.ro/upload/editor/file/pimabetamenutide.pdfIn PDF document text
    • https://nepoo.ro/app/webroot/files/userfiles/files/zixatevepoz.pdfIn PDF document text
    • http://custom-mugs-factory.com/uploadfile/files/joralerimopozuwanubibi.pdfIn PDF document text
    • http://lotusburbank.com/uploads/files/96164632518.pdfIn PDF document text
    • http://pantanalmsnews.com.br/ckfinder/userfiles/files/josuvoxomu.pdfIn PDF document text
    • http://www.synagoge-stommeln.de/ckfinder/userfiles/files/bosazodudefa.pdfIn PDF document text
    • https://fotojursa.cz/userfiles/file/zezetoxozupufa.pdfIn PDF document text
    • http://ipost.mn/ckfinder/userfiles/files/80404923385.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/64977854528.pdfIn PDF document text
    • http://market-oborudovanie.ru/upload/file/21319956530.pdfIn PDF document text
    • https://csam-villepinte.org/uploads/images/file/50385420055.pdfIn PDF document text
    • http://sweet-sugar.de/images/uploadedimages/file/5942419682.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/reduzuwetuvoworavane.pdfIn PDF document text
    • https://etre-cheval.fr/Applications/MAMP/htdocs/etre%20cheval/news_pix/file/virezuneradinogedipexa.pdfIn PDF document text
    • https://mai-avto.ru/upload_files/file/82540464742.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/surofefarufokisu.pdfIn PDF document text
    • http://budaikepkeret.hu/uploads/file/zakatirumeguwux.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=como+ganar+amigos+pdfPDF link annotation
    • 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_off0000b197.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB197 10596 bytes
SHA-256: 075cab36267a9c65994a997390b0161c32cea57eae312dc5531a9d207734fcef
font_01_sfnt_off0000c981.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC981 16616 bytes
SHA-256: fdb0823e301946d990caf1cb4f37a07c78f54aa158d88e7e990ae9e0e5189523
font_02_sfnt_off0000f39c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF39C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1