Malicious PDF — malware analysis report

Static analysis result for SHA-256 77eca4b8ea7cfb7a…

MALICIOUS

PDF

77.1 KB Created: 2021-09-17 19:10:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 7c8f1c05a019c723287364a9c3441101 SHA-1: 84ab66c01b51f1577b675690ef2249e64560bfb0 SHA-256: 77eca4b8ea7cfb7abdd7e95baa24333671f3b9e117ef4c52caa3e2425b2aca02
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to potentially malicious or phishing sites, and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a deliberate attempt to obscure the true destination. The presence of external URIs and the overall structure point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://chcial.ru/uplcv?utm_term=best+virtual+classroom+platform PDF link annotation
    • http://juditphotography.com/picture/userfiles/file/gisareburapejedaw.pdfIn PDF document text
    • http://schule.havonix.com/ckfinder/userfiles/files/xodenobuzasusu.pdfIn PDF document text
    • http://jevades.com/aircraft/fckimages/file/kepagevukuzifunumijowedas.pdfIn PDF document text
    • http://problemconsulting.com/img/download/files/7180523337.pdfIn PDF document text
    • http://cainghienbinhduong.com/uploads/userfiles/file/72824321406.pdfIn PDF document text
    • http://cleanking.net/userData/board/file/4274584398.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411a9ca1bbd---17513463339.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/nevizegabegazudefag.pdfIn PDF document text
    • https://mptradingcompany.com/userfiles/file/kawuloxukeladaxijiwoza.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/33248737166.pdfIn PDF document text
    • http://ballarioarchitetti.eu/userfiles/files/jikevosi.pdfIn PDF document text
    • https://yukkumpulgroup1.com/contents/files/59456423902.pdfIn PDF document text
    • http://rockbond-aac.com/id-admin/fckImages/file/sifemazukegebozebiw.pdfIn PDF document text
    • http://galenbio.com/images/upload/file/4810346250.pdfIn PDF document text
    • https://yourwebcenter.com/files/file/95845402621.pdfIn PDF document text
    • http://sasolution.kr/userfiles/file/tivufikenavun.pdfIn PDF document text
    • https://cmfnepal.org/userfiles/files/87037298170.pdfIn PDF document text
    • http://duetsepolno.pl/userfiles/file/82341852650.pdfIn PDF document text
    • http://nutronicltd.com/userfiles/file/44540655955.pdfIn PDF document text
    • https://airxps.com/userfiles/files/dezikarevimukekebo.pdfIn PDF document text
    • http://musorcentrum.around.hu/files/article/file/31716147807.pdfIn PDF document text
    • https://kiaavcilar.com/upload/ckfinder/files/2128541788.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/juxatobibekuwaleleze.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_off0000c9ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9AB 17112 bytes
SHA-256: 5082d2b0cec0a8f2f989ea4265e1d61197f268b47522010041de90081b49157c
font_01_sfnt_off0000f579.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF579 10756 bytes
SHA-256: 8e9dfe570780fb44ebd15d4f96415e2f6f849c7032cc4eeae3018ac24870f83f
font_02_sfnt_off00010e56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E56 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1