Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf0dfccdc00c0e04…

MALICIOUS

PDF

78.1 KB Created: 2021-10-06 16:46:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 38ea5fb0f5d722f2be76624b068b435d SHA-1: 9408df9246595524d78aba377712c2c3c3d43f71 SHA-256: bf0dfccdc00c0e0423b0b3611a80b17a7b43b614be652bc273fd8748c8737afd
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 external URLs, with one heuristic specifically noting it as a link farm on disposable hosting. The presence of embedded URLs and the nature of the heuristics suggest the PDF's primary function is to redirect users to potentially malicious external sites, likely for phishing or to download further malware. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://coretry.ru/uplcv?utm_term=cbse+class+10+maths+exercise+3.1+solutions PDF link annotation
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/nejavowopofi.pdfIn PDF document text
    • http://phulieumaymacbaoco.com/hinhanh_fckeditor/file/9690432158.pdfIn PDF document text
    • http://jiji.pgo.tw/pic/uploads/files/fudoronupener.pdfIn PDF document text
    • http://royalrep.com/userfiles/files/65540659377.pdfIn PDF document text
    • https://ikitellirezistans.com/upload/files/terabusir.pdfIn PDF document text
    • http://isvpro.com/custom/files/60724799339.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/deridurebizosinepigawidaj.pdfIn PDF document text
    • https://vizesblokk.hu/files/file/suton.pdfIn PDF document text
    • http://mmprogetti.it/userfiles/files/xagal.pdfIn PDF document text
    • http://ptaki.info/imgekoprojekty/files/nopogivumiveli.pdfIn PDF document text
    • http://nasledie-sluck.by/var/upload/file/79523918586.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/23080278785.pdfIn PDF document text
    • http://vo23.ru/upload/file/zifubimugumobozaxadolu.pdfIn PDF document text
    • https://dpt-mh.com/uploads/news/files/41474427369.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/a75639d282d3dae3e2aedb100b274011/juzisuzikatenokovupaxidol.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134f6e3a2395---jujukomisegiwolemigim.pdfIn PDF document text
    • http://indecomavo.pl/userimg/inc/doxatofapu.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/mawonatibobamakovabelin.pdfIn PDF document text
    • http://majstrissmt.eu/www-data/file/nopozawixi.pdfIn PDF document text
    • http://gesundezellen.de/neu/userfiles/file/pedumi.pdfIn PDF document text
    • http://praconsulgroup.ru/pict/file/7234772567.pdfIn PDF document text
    • http://bronia.org/userfiles/file/20734389153.pdfIn PDF document text
    • https://ddnepal.com/assets/userfiles/files/98510868475.pdfIn PDF document text
    • https://suacuasathcm.com/uploads/files/63975711704.pdfIn PDF document text
    • http://nilesk.com/userfiles/file/rokaxipojarakelesixeguzi.pdfIn PDF document text
    • http://timnhanhonline.vn/upload/files/65049677739.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_off0000c594.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC594 11280 bytes
SHA-256: e670915d32b5eeca916cbdbda2ec46b6aec47e58f0cab7fba4e805a42b043fee
font_01_sfnt_off0000dff9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f80b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80B 19104 bytes
SHA-256: ce241dbff597add78604fba13ec6fc3b70aadb1e4179a63934366872256d6070