Malicious PDF — malware analysis report

Static analysis result for SHA-256 f2ef41dd345b0d5f…

MALICIOUS

PDF

84.4 KB Created: 2021-09-19 13:44:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1cdad6f25c1da1867f51aa343382eb18 SHA-1: 2b743b8719a69d6d0c475e50a47be5f51ad61e9f SHA-256: f2ef41dd345b0d5f6b0fa3bb1c8758dd468275c2dd9b99c3df7a804193453d9c
86 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a likely phishing or malware distribution attempt. The ML classifier strongly flagged this PDF as malicious, and the malformed stream length heuristic suggests an attempt to hide malicious content. While no scripts were directly extracted, the structure and embedded URLs point towards an attack pattern focused on redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://irlanc.ru/uplcv?utm_term=x+men+days+of+future+past+full+movie+free PDF link annotation
    • http://msdoubrava.cz/foto/images/file/69326820427.pdfIn PDF document text
    • http://www.vinoplaza.nl/img/upload/files/lareligazulosukakaraj.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/rk7m0m1vtd4hp2vn8m5mmsied9/47309288649.pdfIn PDF document text
    • https://nepalipublisher.com/ckfinder/userfiles/files/dijorabibebosoj.pdfIn PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/26044426675.pdfIn PDF document text
    • http://xn--b1adbbbaeqjtsflbfms0e.xn--p1ai/pict/file/japenaranixotavum.pdfIn PDF document text
    • http://mvsexpo.ru/admin/ckfinder/userfiles/files/78782219145.pdfIn PDF document text
    • https://adci.vn/data/upload/file/kapomorazobedab.pdfIn PDF document text
    • https://pass-eco-energies.com/ckfinder/userfiles/files/rulibes.pdfIn PDF document text
    • https://zaindu.drogomedia.com/files/galeria/files/norapapuluvofisilutode.pdfIn PDF document text
    • http://pomelieagency.com/userfiles/files/bivanewifimifotavapu.pdfIn PDF document text
    • http://www.macrolepidoptera.hu/userfiles/files/63272346132.pdfIn PDF document text
    • http://homelife-superstars.com/image/files/14881985266.pdfIn PDF document text
    • http://indagosrl.it/userfiles/files/bumupemudunefenekekanavat.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/11807485445.pdfIn PDF document text
    • https://cvconstructionsgoa.com/pharma/admin/userfiles/file/87558210051.pdfIn PDF document text
    • http://fkhd.cz/data/img/70933935727.pdfIn PDF document text
    • http://dsacare.com/admin/uploads/file/76117712586.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/86572679787.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131a0a0933aa---13672676794.pdfIn PDF document text
    • https://speak82.com/_UploadFile/Images/file/19714077130.pdfIn PDF document text
    • https://kapokcmassage.com/uploads/files/202109050206484363.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/fepegasuxakidodonujapak.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_off0000e809.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE809 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001001b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1001B 16420 bytes
SHA-256: 4b168a76c1a806f001fe03afa17d1f3a8f363de019ea2947af4e2c70f53558d1
font_02_sfnt_off00012a71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A71 10944 bytes
SHA-256: 67d607716c00264cd37cb39895c58700104fdf31072c7103a53f927669559502