Malicious PDF — malware analysis report

Static analysis result for SHA-256 756cb3e3820347d8…

MALICIOUS

PDF

84.9 KB Created: 2021-10-07 12:42:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: b117321dc120f9fdf5fc7bb3f262eb6a SHA-1: 93a464c830e93943a33f02df7f0ae1e122a341ad SHA-256: 756cb3e3820347d8b6ff58155f9c3b7f6693f7a2db96175eb50c67cff4fe22ae
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a large number of embedded URLs, many of which point to disposable hosting and appear to be part of a link farm. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is designed to redirect users to external, potentially harmful, content. No scripts were extracted, but the sheer volume of suspicious links points to a malicious intent, likely for SEO manipulation or to serve as a landing page for further exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://nomylo.ru/uplcv?utm_term=what+does+solo+mean+in+spanish PDF link annotation
    • http://bestbelly.org/content/files/files/11817409920.pdfIn PDF document text
    • http://rudolphi.nu/userfiles/file/99448407537.pdfIn PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/75130754414.pdfIn PDF document text
    • http://kondicionery-lobnya.ru/upload_picture/file/25848723570.pdfIn PDF document text
    • http://giaodantanthaison.com/Images_upload/files/fujiturifesilagubigagede.pdfIn PDF document text
    • http://philipsphotographystudio.com/jevem.pdfIn PDF document text
    • http://robbymakka.com/userfiles/file/34988850395.pdfIn PDF document text
    • https://anninhsieuthi.online/upload/files/dajimoniwez.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/2e2335ee8a59bb6209038af7374e48de/ralixodopanujeleved.pdfIn PDF document text
    • http://xn--80aguejfegacgj0ad.xn--p1ai/pict/file/bokujudibavudadowe.pdfIn PDF document text
    • http://www.arborvitae.cz/ckfinder/userfiles/files/nivazozexatutadonefaraz.pdfIn PDF document text
    • http://finproekt-msk.ru/userfiles/file/tovepajuwizogutumesu.pdfIn PDF document text
    • http://musicincw.com/fckeditor/userfiles/image/lenojibikenunigo.pdfIn PDF document text
    • http://world-spa-resorts.com/dok/94308889142.pdfIn PDF document text
    • http://inistor.com/ufiles/files/42235521357.pdfIn PDF document text
    • https://energooptima.hu/upload/File/tevukufajakirulizuvebes.pdfIn PDF document text
    • http://france-ex.com/images/blog/file/zifinugedezokuvexok.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161404b0ea03af---5636321866.pdfIn PDF document text
    • https://protradingindia.net/userfiles/file/36405569031.pdfIn PDF document text
    • https://agri-mal.pl/userfiles/file/71973286366.pdfIn PDF document text
    • http://keitbg.com/images/files/xavit.pdfIn PDF document text
    • http://kleinschaden-expert.com/userfiles/file/34794843066.pdfIn PDF document text
    • https://orderpoet.com/ckfinder/userfiles/files/jizerikejufak.pdfIn PDF document text
    • http://hferrynetworks.com/FileData/ckfinder/files/20211003_78727BFA873B277D.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_off0000def5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF5 10548 bytes
SHA-256: d113b7ffffbc6b6a787c47dd19c94a29a0378108fc27e03f7b0970fd298ddbd8
font_01_sfnt_off0000f6ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ee0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EE0 21524 bytes
SHA-256: 75bc6dfe28bd64052f286952a69a0b95d1fa41cb818094154e3d53bc0bf11dcd