Malicious PDF — malware analysis report

Static analysis result for SHA-256 d23c276c2fed2c01…

MALICIOUS

PDF

83.5 KB Created: 2021-09-19 04:57:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0b3ee229eed1407e6a01d1a7668c9329 SHA-1: d1b33e9c21182010c444ee0d462f8e522e21435a SHA-256: d23c276c2fed2c01a00d3e363830add80ae28452d79ae3c770332853c5ef31d2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to potentially compromised or disposable hosting. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics indicate a pattern of link farming and exploitation of content management systems. While no scripts were extracted, the ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://ambient-interier.cz/files/files/kirokezebusagilixebopax.pdf In PDF document text
    • http://hnyinfeng.com/d/files/14029206357.pdfIn PDF document text
    • http://thegioioto.store/upload/files/4615629900.pdfIn PDF document text
    • http://186086.com/upload/files/fodugavemirifetim.pdfIn PDF document text
    • http://improntediteatro.it/userfiles/files/newidebepiwimajulazijex.pdfIn PDF document text
    • http://skipjackpoke.com/ckfinder/userfiles/files/97866700001.pdfIn PDF document text
    • http://thuaphatlailongthanh.com/upload/contentFile/minhchau/file/2531822956.pdfIn PDF document text
    • https://computerzone.pk/file/25129280356.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/161343121841c3---zelofibabaga.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/kcc5oi6u95li3tthqhs2qloa22/kukilinuwubasanixol.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613e7dd3bfd3f---bunedozevalimizoxok.pdfIn PDF document text
    • http://vantaidongsaigon.com/uploads/files/30960845384.pdfIn PDF document text
    • http://monticellotownship.org/userfiles/file/35853117399.pdfIn PDF document text
    • https://galaxytraining.examinationonline.com/files/zaviruw.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614653ee1dc3d---lurejegesofokibibesazo.pdfIn PDF document text
    • https://hbphoto.ca/resimler/files/gavotefuvufuragabutufize.pdfIn PDF document text
    • https://dwitunggaljaya.com/sitefiles/file/kuzule.pdfIn PDF document text
    • https://meritumptt.pl/dokumenty/file/fenakefidewenetubu.pdfIn PDF document text
    • https://98ing.com/upload/ck/files/20210901_130343.pdfIn PDF document text
    • http://gvs-russia.ru/admin/ckfinder/userfiles/files/7850341672.pdfIn PDF document text
    • http://yarpb.ru/pic/userfile/lurobebomebakurivamit.pdfIn PDF document text
    • http://huspanda.com/data/ckfinder/files/83516423279.pdfIn PDF document text
    • http://richmediahouse.com/admin/uploads/file/42640487870.pdfIn PDF document text
    • http://xn----dtbsgbucafmmaf.xn--p1ai/servimages/editor/files/86623837014.pdfIn PDF document text
    • http://ldkxzzs.com/images/userfiles/file/5199692574.pdfIn PDF document text
    • http://spartaksedlec.cz/spartaksedlec/userfiles/file/23622233553.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=building+construction+illustrated+6th+edition+pdf+free+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_off0000dc59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC59 11304 bytes
SHA-256: 181ad23cd7b1f936ba6f65c1aae0b384f8c78b663842d94732660f5e1d3e09ba
font_01_sfnt_off0000f6ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6BA 18936 bytes
SHA-256: 3fa26bc69d6136ab808a7ff7b91b0195f314a7189331ef9b11602e5cbcfdf992
font_02_sfnt_off00012740.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12740 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1