Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d1b1a4b8e6b33df…

MALICIOUS

PDF

77.4 KB Created: 2021-09-17 15:08:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: e45bf9dedd9829f8760b4413f6f05a3a SHA-1: 05f92edc93c6da04536f9a9d30e1676ecaa31861 SHA-256: 4d1b1a4b8e6b33dfeba83c146e689376f4ac5498ce4af43575b8b3e833737301
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which are hosted on disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to download further payloads or lead to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://zlato-eu.cz/upload/files/talezokefad.pdf In PDF document text
    • http://tuderprogettazione.it/userfiles/files/70261519389.pdfIn PDF document text
    • http://lafiestadelmoto.cz/files/file/mumebiwi.pdfIn PDF document text
    • http://digjamaica.com/app/webroot/files/55593184660.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/80188685741.pdfIn PDF document text
    • http://agro-pasz.pl/ckfinder/userfiles/files/63622806934.pdfIn PDF document text
    • https://fiscconsulting.com/userfiles/file/86864165410.pdfIn PDF document text
    • https://www.algeos.com/js/ckfinder/userfiles/files/60550661094.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16130bc7f2df19---giwatusuvavesapiwanom.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613f73d148ea7---fubegawafawozi.pdfIn PDF document text
    • http://krajinar.cz/soubory/files/bulikiwafelizijitagaxu.pdfIn PDF document text
    • http://whdhgs.com/uploads/file/20210907084438275.pdfIn PDF document text
    • https://kamionosnyelvlecke.hu/userfiles/file/bokowuwasezesez.pdfIn PDF document text
    • http://caramelitos.sk/files/54928744359.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/bonuvinexowolonilajapu.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/42777856780.pdfIn PDF document text
    • http://mrpennarak.com/user_file/file/94061061330.pdfIn PDF document text
    • https://ikorti-iao.com/userfiles/files/tebimojuxobejawijofulitox.pdfIn PDF document text
    • https://agrocare.ro/ckfinder/userfiles/files/12319131704.pdfIn PDF document text
    • https://chupwo.com/editor_upload/file/merib.pdfIn PDF document text
    • http://an-ocn.ru/ckfinder/userfiles/files/bujuwuzidakofetetav.pdfIn PDF document text
    • https://magatek.com/documents/file/jiratila.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=convert+the+degree+measure+to+radian+measurePDF 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_off0000c94c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC94C 10844 bytes
SHA-256: 3c556ebbfd57f82f5f21ad968a3199f760d7d44003ef75da8ba5575130aff5bd
font_01_sfnt_off0000e203.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE203 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA15 17620 bytes
SHA-256: 71cde5e318893b4077531e827365c4b539d933c3ec6626577d034b7ab3ecea67