Malicious PDF — malware analysis report

Static analysis result for SHA-256 75281b636a4ffe4e…

MALICIOUS

PDF

79.5 KB Created: 2021-09-14 08:56:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 7be65d90961058a2bc5dd424dc3c562f SHA-1: 2d39e473ca5c2719b68c36e843036fc9678bea52 SHA-256: 75281b636a4ffe4e9445e1f0e34cc1050dab6d32407effae259e7f53d9d618a1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a high volume of links pointing to potentially disposable domains, suggesting a phishing or spam campaign. While no scripts were explicitly extracted, the presence of numerous embedded URLs and the nature of the heuristics point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 https://home-consult.lu/userfiles/files/48839831003.pdf In PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/wuwejerovikedenezivon.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/nubolixuzowilanak.pdfIn PDF document text
    • http://dr-temt.ru/images/file/53723445712.pdfIn PDF document text
    • http://ventilatoryzlin.cz/images/file/72768522698.pdfIn PDF document text
    • https://cebubigsellers.com/userfiles/file/81670209507.pdfIn PDF document text
    • http://oembag.com/uploads/files/202109031810446729.pdfIn PDF document text
    • http://www.gamylai.vn/uploads/files/45651843848.pdfIn PDF document text
    • http://underbutter.cz/download/foto/zataranifeniwuwilu.pdfIn PDF document text
    • https://groupunsur1.com/contents/files/vexuvipefaguvage.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/48429485232.pdfIn PDF document text
    • http://tartak-monis.pl/tartak/images/file/wiwitewukux.pdfIn PDF document text
    • http://rucodelniza.ru/userfiles/file/jupigolisolugomamapamumo.pdfIn PDF document text
    • http://egitara.com/upfiles/files/ramevufuwafenavov.pdfIn PDF document text
    • http://gameometria.com/assets/ckfinder/core/connector/php/uploads/files/fulunimurinevivijux.pdfIn PDF document text
    • http://hantechwelding.com/userfiles/file/2021091104101773499.pdfIn PDF document text
    • http://pololanna.com/user_img/files/12722504363.pdfIn PDF document text
    • https://grnca.org/img/files/files/98703878586.pdfIn PDF document text
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/wudutikutuxevejumupulenin.pdfIn PDF document text
    • https://togelunited4d.com/contents/files/14215580160.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/kuxowabejitivaxu.pdfIn PDF document text
    • http://hzqzg.com/d/files/wazulama.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/73778596655.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=best+sniper+games+for+android+offlinePDF 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_off0000d2c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2C0 17468 bytes
SHA-256: fb1608349c916ac4a10df076cfdd030065d52e203002372e8ab8e42e33a917d4
font_01_sfnt_off0000ff73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF73 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001178a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1178A 10892 bytes
SHA-256: 5aedf4b03f4b5fb71fa89f9278aad3cf44708337c5317161e048804d4c21de6b