Malicious PDF — malware analysis report

Static analysis result for SHA-256 90bd13da040d9238…

MALICIOUS

PDF

81.2 KB Created: 2021-09-11 23:05:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a73c7f8efbdb9b66c324fd8f1df838fc SHA-1: d3e94a2b3b5bed3ba5108079131430889e5bbd6e SHA-256: 90bd13da040d9238b3a6c9e9239a8867e4075e6d63d55ca91824c1bc5b111b2f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to a link farm, suggesting a tactic to manipulate search engine results or distribute further malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://serviphony.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/finidomebegifomemew.pdf In PDF document text
    • https://cauthinh.com/luutru/files/wogavosulisoguvowukefu.pdfIn PDF document text
    • http://gaestehaus-am-erlkoenig.de/img/editor/file/putajirulugopudorufira.pdfIn PDF document text
    • http://studiotecnicoarduini.eu/userfiles/files/munafunuwu.pdfIn PDF document text
    • http://dlshixiang.com.cn/ckfinder/userfiles/files/1843018870.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/raweloxelelojewa.pdfIn PDF document text
    • http://netart.hu/userfiles/file/sijafekapinidatebofu.pdfIn PDF document text
    • https://citrasas.com/ckfinder/userfiles/files/11932775414.pdfIn PDF document text
    • https://www.aledrukujemy.pl/ckfinder/userfiles/files/86114490805.pdfIn PDF document text
    • http://topimmigrationlawyer.org/ckfinder/userfiles/files/68925100025.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135743889d8f---wevuxedijalo.pdfIn PDF document text
    • http://royalgroup.at/tmp/80023252650.pdfIn PDF document text
    • http://rezidencianestor.sk/app/webroot/files/ckeditor/files/tanirifajejop.pdfIn PDF document text
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/83817169872.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/35d33567fe3a3f5759aa768de04b1b58/tokubutiwabovinez.pdfIn PDF document text
    • http://chapraptti.org/userfiles/file/61228931400.pdfIn PDF document text
    • http://joy05.com/_UploadFile/Images/file/34280030678.pdfIn PDF document text
    • https://kompaspt1.com/contents/files/95896758484.pdfIn PDF document text
    • https://bunianco.com/other_files/File/99932631074.pdfIn PDF document text
    • https://sanidom.pl/img/file/21509524212.pdfIn PDF document text
    • http://elpijisystem.com/file/xelaxam.pdfIn PDF document text
    • https://jpt.mysmartedu.com/uploadimages/files/1915828311.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/33807528084.pdfIn PDF document text
    • http://sungwoo-n.com/userfiles/file/mifumubim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=rakesh+maria+let+me+say+it+now+pdf+downloadPDF 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_off0000d53e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD53E 11100 bytes
SHA-256: b6fda925c925faf739a79d34ed396aa423afcfc9e408d72cd9b1c515ec7acd73
font_01_sfnt_off0000ef01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF01 18440 bytes
SHA-256: 90fde28332a922c6b13f9c4578db7962f755c130329795ca04141759bf84bf52
font_02_sfnt_off00011f22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1