Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3d25bc993029990…

MALICIOUS

PDF

71.7 KB Created: 2021-10-03 10:47:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a65973a6bb38f5f85d1c045d6c719758 SHA-1: 6ff8dc03477791d9919fe2f880482eabae1871a3 SHA-256: c3d25bc993029990f2c9eecf6e982a15a4248ed30df20584c73e8d446d02127c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to domains that appear to be part of a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, not containing user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://timnhanhonline.com/upload/files/visoradojunitawisoz.pdf In PDF document text
    • https://confidence-ist.com/ckfinder/userfiles/files/tolaloj.pdfIn PDF document text
    • http://ozkayalartrans.com/userfiles/file/17106455235.pdfIn PDF document text
    • http://studiotecnicostradi.eu/userfiles/files/73088543384.pdfIn PDF document text
    • http://allergyc.news-read.com/upload/files/89808915385.pdfIn PDF document text
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/30452669489.pdfIn PDF document text
    • http://alexdisinfestazioni.com/userfiles/files/26538834608.pdfIn PDF document text
    • http://mynotary.ca/sites/all/sites/mynotary.ca/files/97548631484.pdfIn PDF document text
    • https://gemma.lucien-sv.info/uploads/files/613d955f1d86f.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/tojukaxosusekimonuti.pdfIn PDF document text
    • http://pharmabiosolutions.com/filespath/files/20210906225343.pdfIn PDF document text
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/59126642287.pdfIn PDF document text
    • https://doanhnghiepvietnam.niengiamdoanhnghiep.vn/img_duhoc/files/nilopipixoli.pdfIn PDF document text
    • https://arrayamed.com/userfiles/file/jijuxabopanu.pdfIn PDF document text
    • http://ydtmuhendislik.com/ckfinder/userfiles/files/kitetuvukabefonagumevez.pdfIn PDF document text
    • http://kustari.net/userfiles/file/73178067146.pdfIn PDF document text
    • https://bibliothequedesarts.ch/ckfinder/userfiles/files/jeborudodizaluzonozusa.pdfIn PDF document text
    • https://bloomlight.pl/_bloom/file/jorabakuwuni.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/62625816961.pdfIn PDF document text
    • http://thai-apsproducts.com/file_media/file_image/file/pawegemefazadogovidebok.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/rozozinepadelaw.pdfIn PDF document text
    • http://shopcloud.cloud/ckfinder/userfiles/files/91344634044.pdfIn PDF document text
    • http://kameleonhastanc.hu/files/file/topoke.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614bad2f3f788---80262129907.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614dbd6d16167---87804115301.pdfIn PDF document text
    • https://sledovani.gpshlidac.cz/www/userfiles/files/gajogedokesa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=examples+of+silicatesPDF 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_off0000b53f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB53F 10520 bytes
SHA-256: a18fc9aef229d3e706aa3f9d5b1d36fc55b8621303ca0ac89634a6b964f0bdb8
font_01_sfnt_off0000cd45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD45 17040 bytes
SHA-256: f074685b2314c7552827e7f4ac34cfb53c1aafc2e234eb8b49b7cae17a758b14
font_02_sfnt_off0000f8ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1