Malicious PDF — malware analysis report

Static analysis result for SHA-256 c24368681498458b…

MALICIOUS

PDF

84.6 KB Created: 2021-09-18 01:31:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dfd7b94dd42b2c67840a412539a76bd5 SHA-1: 99c7d41a9dd5ad1e0c575efa52864afb9fda7fb5 SHA-256: c24368681498458b077a32fbb6d1ee3a3e2183b759988f379bfbbb72a5fa4d07
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the numerous extracted URLs suggest the document's primary purpose is to redirect users to a collection of other PDF files hosted on potentially disposable domains. No scripts were extracted, but the presence of embedded URLs and the link farm behavior points towards a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://minhledtran.com/luutru/files/5907482263.pdf In PDF document text
    • http://aeusjtu.pretty-match.com/upload/files/futopebugaf.pdfIn PDF document text
    • http://djpress.pl/Image/files/27467665819.pdfIn PDF document text
    • https://ehotelgateway.com/bot/ckfinder/uf/files/metifipitijigewajilesep.pdfIn PDF document text
    • https://ratsimae.ee/media/contents/file/lataboxudujasosufasajuvev.pdfIn PDF document text
    • http://interwork.sk/userfiles/file/dimewovok.pdfIn PDF document text
    • http://kastely-vacduka.hu/fileok/file/xolederunedawezilesodet.pdfIn PDF document text
    • https://icoachyou.biz/images/ckeditor/files/zilabiwotabanapawuzaju.pdfIn PDF document text
    • https://udruga-invalida.hr/files/56917816462.pdfIn PDF document text
    • https://bitree.ru/ckfinder/userfiles/files/sobuxaxamosanin.pdfIn PDF document text
    • https://mayxaydunghoangphuc.com/userfiles/files/wagazemezinizoku.pdfIn PDF document text
    • https://foodphotoshop.com/userfiles/files/sizeru.pdfIn PDF document text
    • http://daiichibus.vn/uploads/news_file/kujoludivenovofaxiduteje.pdfIn PDF document text
    • https://rumahbaruku.com/contents/files/duxuxizene.pdfIn PDF document text
    • https://simbhaolipower.com/images/file/97719679757.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/51107429795.pdfIn PDF document text
    • http://lambanghieuquangcaogiare.net/vietkiendo/upload/file/xujukatosul.pdfIn PDF document text
    • https://goez1.com/10005001208290177/ckfinder/userfiles/files/90132981796.pdfIn PDF document text
    • http://heizler.hu/files/file/zazaxodav.pdfIn PDF document text
    • http://yishiweb.com/upfiles/files/20210910_225101.pdfIn PDF document text
    • http://chornakorn-packing.com/ckfinder/userfiles/files/88926378077.pdfIn PDF document text
    • https://quizai.com/uploads/files/bisedadafebijuk.pdfIn PDF document text
    • http://ceroki.com/image/files/33232826461.pdfIn PDF document text
    • http://dietmoiquangle.com/webroot/img/files/58738809326.pdfIn PDF document text
    • http://lnv-cnc.gr/userfiles/file/16727359329.pdfIn PDF document text
    • http://aquatherm-graz.at/files/74523770568.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=tap+tap+android+appPDF 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_off0000e7df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7DF 10000 bytes
SHA-256: eabc034495ec73b48ae6c2a5d724f62f87e144cbcc291cb4b348c09d546e6d1b
font_01_sfnt_off0000fe14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE14 18056 bytes
SHA-256: ac7e3c9d474d80d449df66834587fb5169d90c1f7f685b22034aee00bdf015e4
font_02_sfnt_off00012d02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D02 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1