Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4246e937ffffef6…

MALICIOUS

PDF

73.4 KB Created: 2021-09-10 01:29:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9a5ab0b4bb070804b4ad379e35bd4a7d SHA-1: 5eebc3ddb6cde1df448abfc8629f2ac24c22cf5c SHA-256: d4246e937ffffef6118770cc4af53684bc5111bc9e4d2f7cf511b50411c461c0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous external URIs, many pointing to disposable domains and exhibiting link farm characteristics, suggests a phishing or malware distribution attempt. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

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://cvzona.lt/resources/img/files/28464362123.pdf In PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613714d4beafb---60053447940.pdfIn PDF document text
    • http://lactopad.com/uploads/files/36397102048.pdfIn PDF document text
    • http://synerfreight.com/syner_upload/images/files/wewiku.pdfIn PDF document text
    • https://www.kuwaitpolyurethane.com/ckfinder/userfiles/files/bugodukapumoxutedesop.pdfIn PDF document text
    • http://olivetheater.com/userData/board/file/bazufaxufiruvuxen.pdfIn PDF document text
    • http://pokorny-podlahy.cz/UserFiles/File/rolimukokigusa.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/84297758291.pdfIn PDF document text
    • https://bd-sokolovska.eu/userfiles/file/rijowafin.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/penezudubosu.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/s67bcn80mkqgh3klukcnrc8dkl/44540082731.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/23199700062.pdfIn PDF document text
    • https://supermagnum-bg.com/userfiles/file/nopasakotulolaxixubej.pdfIn PDF document text
    • http://henskeschildersbedrijf.nl/upload/benisakogizasofamiva.pdfIn PDF document text
    • http://nollve.com/img/editor/image/file/mubovegifesokuzi.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/favugi.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/saxobowevi.pdfIn PDF document text
    • http://sakem.org/userfiles/files/namaxuwuwevi.pdfIn PDF document text
    • http://manisafar.com/basefile/marcosafarir/files/wisogilejujot.pdfIn PDF document text
    • http://monteconsultants.com/image/upload/File/31512652311.pdfIn PDF document text
    • http://xn--90afqerdlt1f.xn--p1ai/admin/ckfinder/userfiles/files/tizasiwagakamoxixofoxiw.pdfIn PDF document text
    • http://goldenpeak.it/userfiles/files/xixemokepalumekilovinu.pdfIn PDF document text
    • http://falegnameriacastiglione.it/userfiles/files/wolaraderodo.pdfIn PDF document text
    • http://ttc-investco.com/img/files/34985779516.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=hanuman+chalisa+original+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_off0000bd7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD7E 16228 bytes
SHA-256: 280de012eb769a2d67d25ff9721bfa5cc8ef715f3fa271d9244eb1cd1be35388
font_01_sfnt_off0000e708.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE708 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF1F 10928 bytes
SHA-256: d2df0fd3ae3f4882d26d1e633aefb0cbe07f61144b080647810303c0edf6ac27