Malicious PDF — malware analysis report

Static analysis result for SHA-256 3205251f45595bf4…

MALICIOUS

PDF

70.4 KB Created: 2021-10-02 09:58:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 843b1079b9fda79d1074fb08befcb9cb SHA-1: 25d7d16dc92ca9124207ca662714ce315a56d71d SHA-256: 3205251f45595bf425820683a0f9bab77f76ab1a8ed5d629fc0c3f2e3690ec6e
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a high number of embedded URLs pointing to various domains, many of which appear to be disposable or used for link farming. The ML classifier strongly indicated maliciousness, and the presence of numerous external URIs suggests an attempt to redirect users to potentially harmful content. While no scripts were explicitly extracted, the PDF structure and URL distribution are indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 4

  • 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://huntic.ru/uplcv?utm_term=persistent+hyperparathyroidism+after+parathyroidectomy PDF link annotation
    • http://xn--38-mlcqjbufcz6h.xn--p1ai/userfiles/file/mebuxo.pdfIn PDF document text
    • https://protrialse.eu/files/files/56590946329.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/52903270841.pdfIn PDF document text
    • http://thegioimercedes.com/upload/files/83001231560.pdfIn PDF document text
    • http://erex.hu/upload/file/9590405328.pdfIn PDF document text
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/86375633575.pdfIn PDF document text
    • http://oskarmak.com/userfiles/file/18295040378.pdfIn PDF document text
    • http://ipost.mn/ckfinder/userfiles/files/12714411619.pdfIn PDF document text
    • https://refoca.cenacat.org/yiicms/ckfinder/userfiles/files/22584522034.pdfIn PDF document text
    • http://feg.vn/uploads/files/89890173786.pdfIn PDF document text
    • http://haenuri.net/ckupload/files/viwawuxefokul.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/15244322886.pdfIn PDF document text
    • http://postelezmasivu-brno.com/ckfinder/userfiles/files/zezobozuvavisem.pdfIn PDF document text
    • http://indcms.testingmachines.com/images/file/96094711722.pdfIn PDF document text
    • https://1snrpaulista.com.br/ckfinder/userfiles/files/nafaliragifebojipeja.pdfIn PDF document text
    • https://cargobull.cz/res/file/6843850460.pdfIn PDF document text
    • http://younewstoday.com/task/userimages/file/67559120566.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f08d5d25a2---wubenixedasusoxeg.pdfIn PDF document text
    • http://hakasasi.id/userfiles/file/rajezadivadexoz.pdfIn PDF document text
    • https://el-tall.pl/pics/file/67272010656.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/546nvuf5e145v3nkiahoklvqt7/40837025546.pdfIn PDF document text
    • http://france-ex.com/images/blog/file/80229521297.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_off0000aecb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAECB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c6dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6DD 17156 bytes
SHA-256: 108e5337e9f4adb4674af9b3255d546f942811b2e77856e4833f6ea364644e34
font_02_sfnt_off0000f277.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF277 10956 bytes
SHA-256: 43fe5d3ce27954a1110d80d3d0a9b16106ecdbdf423d0ee8406b46a8ec577456