Malicious PDF — malware analysis report

Static analysis result for SHA-256 81fb7c8057e96ae5…

MALICIOUS

PDF

73.7 KB Created: 2021-09-29 02:58:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 41456e44d6e076e058ad861bf6985605 SHA-1: 2bf7c9eb6398d5dc126713debadf9da563a46d20 SHA-256: 81fb7c8057e96ae5f311b1b506b60635490b4870be5a17dea08af45d81819150
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. It contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a strong intent to redirect users to potentially harmful sites. The presence of external URIs and the 'link farm' heuristic suggest the primary goal is to direct users to external content, likely for malicious purposes such as phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://nomylo.ru/uplcv?utm_term=wallpaper+angry+birds+for+android PDF link annotation
    • http://digitalpolicycouncil.org/imagenes/file/67865610763.pdfIn PDF document text
    • http://westfallassociates.com/documents/file/61332993776.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/misogosojowamoto.pdfIn PDF document text
    • http://rezidencianestor.sk/app/webroot/files/ckeditor/files/lekimixajevutulu.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161420899f31fd---murenilegelibetuju.pdfIn PDF document text
    • http://020tzs.com/baige/images/userfiles/file/14739993772.pdfIn PDF document text
    • https://mimpishiosatu.com/contents/files/sasanavefizirapegotewete.pdfIn PDF document text
    • https://angelsolutions.ro/ckeditor/ckfinder/userfiles/files/72433194382.pdfIn PDF document text
    • http://linpus.com/app/webroot/userfiles/files/sotefabepagiwesakeg.pdfIn PDF document text
    • https://lhorizon.ca/uploadHorizon/file/77854622909.pdfIn PDF document text
    • http://brukbet.com/user_images/file/suzekedesuve.pdfIn PDF document text
    • http://abbwingslynnhaven.com/uploads/files/32990399598.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210906/file/16309406535989.pdfIn PDF document text
    • https://tw-itemaos.com/ckfinder/userfiles/files/44979216826.pdfIn PDF document text
    • http://nineslash.com/user_file/file/98193254646.pdfIn PDF document text
    • http://pegastelco.com/pictures/files/12128731639.pdfIn PDF document text
    • https://mobisteelegypt.net/userfiles/file/tosugonebejukesekaximut.pdfIn PDF document text
    • http://www.hz-kontejnery.cz/ckfinder/userfiles/files/82357857442.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/gb9t6npi8sm8nqr8n3ltlf95pf/nasojobulimozo.pdfIn PDF document text
    • https://asiapharma.la/files/files/xirimunozanifi.pdfIn PDF document text
    • https://evenements.gipso.org/ckfinder/userfiles/files/zonitexotonaf.pdfIn PDF document text
    • http://e-sheremet.com/img/sajoxesefejifalakavaso.pdfIn PDF document text
    • https://dazhonghua1688.com/ckfinder/userfiles/files/gafigogukagozipasazavet.pdfIn PDF document text
    • http://agppi99.pretty-match.com/upload/files/27349431812.pdfIn PDF document text
    • https://tortugafilms.ca/adminfiles/file/wujejefoba.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_off0000b9a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d1ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1BA 10820 bytes
SHA-256: afc10678edb8497001e7dac29fc332c0f7b4f8ea6b12b6906ca1225c2c06ff0f
font_02_sfnt_off0000ea55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA55 17712 bytes
SHA-256: cd08c972ab1c2d7c461b93bc795dd8a4d70c0e8e0307e2362757d5c4905cfc88