Malicious PDF — malware analysis report

Static analysis result for SHA-256 81569b88c4722916…

MALICIOUS

PDF

85.8 KB Created: 2021-09-16 07:26:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6c20b5e2570773988587e002690f1c34 SHA-1: 44a41c38408a3008998b92450db8341a595786b8 SHA-256: 81569b88c4722916a0691458deb1226c4586720f7ef46dbfa574ad3f0e5281ad
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with many pointing to disposable domains, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a malicious document designed to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://boilerservis.ru/uploads/files/34413724891.pdf In PDF document text
    • https://bozoklar.org/ckfinder/userfiles/files/fuzurijagegetasomenaluvef.pdfIn PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210907_808C34A86FE15764.pdfIn PDF document text
    • http://fkjz.cn/upload/files/2021/09/202109070120449217.pdfIn PDF document text
    • https://globalcircle.club/userfiles/file/13976033535.pdfIn PDF document text
    • http://baheth24aqari.com/ckfinder/userfiles/files/94032306284.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16131ab644bac3---vobinizabinokekelabetu.pdfIn PDF document text
    • http://dolphinkorea.com/files/files/besukexudexupi.pdfIn PDF document text
    • http://domusanna.it/userfiles/files/51929683895.pdfIn PDF document text
    • https://thehideawayresortpattaya.com/userfiles/files/ligelefideza.pdfIn PDF document text
    • http://brenderup.ro/mm/file/ribenunemazexofofa.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/tibar.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/15395011625.pdfIn PDF document text
    • https://divetechmarine.com/contents/files/49178275656.pdfIn PDF document text
    • http://arcadia-fitness.es/userfiles/file/13167714662.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/12693734546.pdfIn PDF document text
    • http://vitalenzyme.com/uploads/fckupload/file/ziredokanasimobexi.pdfIn PDF document text
    • http://yeosingol.com/FileData/ckfinder/files/20210910_725BBF95F61B743A.pdfIn PDF document text
    • http://engcaphone.com/_UploadFile/Images/file/56457189661.pdfIn PDF document text
    • http://getampedmag.com/ckfinder/userfiles/files/novineloborexe.pdfIn PDF document text
    • http://laros.cz/UserFiles/file/21376007773.pdfIn PDF document text
    • http://woodlander.sk/grafika/file/8865776844.pdfIn PDF document text
    • https://www.padanguparduotuve.lt/ckfinder/userfiles/files/nakagawomev.pdfIn PDF document text
    • http://stark-tools.ru/images/uploaded/luvupofo.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/wodesejotovoneraxesop.pdfIn PDF document text
    • https://basisangka.com/contents/files/nijepeza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=tamagotchi+android+gamePDF 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_off0000ee6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE6A 16780 bytes
SHA-256: d8fcf4fc000652834af55a9acc095f2b85602de2d281b884385643374d681339
font_01_sfnt_off000119e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000131fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131FD 10564 bytes
SHA-256: c6d726dc3f78e5f9af3fc00e3239187f5301c2b5beb27f12a6fcb4fd9d587d0c