Malicious PDF — malware analysis report

Static analysis result for SHA-256 a38c56dc8be073a2…

MALICIOUS

PDF

84.7 KB Created: 2021-09-16 00:43:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f978f8cf23dcb92d529b5aeecc10c419 SHA-1: 0e7b736202b20c80983ef4b8441652e1a000d9c7 SHA-256: a38c56dc8be073a2ee2cb83b544d72b4964a43193fa40072000165b588a557bb
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or other disposable hosting. The ML classifier strongly indicates maliciousness, and the presence of a link farm suggests an attempt to redirect users to potentially harmful content or for SEO manipulation. The primary attack pattern observed is the use of a document as a link farm, likely as part of a phishing or content distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://irlanc.ru/uplcv?utm_term=demon+slayer+kimetsu+no+yaiba+the+movie+mugen+train+digital+release PDF link annotation
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/40cc3f1d4377e13e92b28ddb7ac7c0cd/nurudirevovetizideloz.pdfIn PDF document text
    • http://psychologadamczak.pl/userfiles/file/61040100439.pdfIn PDF document text
    • https://am-system.eu/ckfinder/userfiles/files/guraje.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/gezaguduxemozo.pdfIn PDF document text
    • https://thehouseconcert.com/ckfinder/userfiles/files/83640034079.pdfIn PDF document text
    • https://castilloexterior.org/ckfinder/userfiles/files/rarirudaxulajejijopawop.pdfIn PDF document text
    • https://alebusph.centralcms.cloud/galeria/files/93544231174.pdfIn PDF document text
    • http://bluebossa.pl/files/file/94840061845.pdfIn PDF document text
    • http://odesignlab.ru/admin/ckfinder/userfiles/files/giwubokeseselekizida.pdfIn PDF document text
    • http://proxima-design.cz/files/file/52428030781.pdfIn PDF document text
    • http://jlssj.com/qianzi/upfile/case_editor/file/89135367064.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/nawupirewezipizewi.pdfIn PDF document text
    • http://vishwkarmaenterprises.com/webroot/img/userfiles/files/52139963924.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/kipafeleniv.pdfIn PDF document text
    • https://collinite.pl/userfiles/file/sezusaluxum.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/69968042261.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/161397b613b51b---76102108346.pdfIn PDF document text
    • https://lenaoyunlar.net/calisma2/files/uploads/lolikom.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/585491b8166df529fd654cb12f15eec1/93458378303.pdfIn PDF document text
    • http://vibrobreaker.com/files/files/pipaminumonikewiva.pdfIn PDF document text
    • https://songhong.info/userfiles/file/60171458223.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/91951256775.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/12decf5c8f94383c5f7a6d4b5f9e1718/vuxinuloxigul.pdfIn PDF document text
    • https://vinatech.com/userfiles/file/32161087914.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_off0000dea7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEA7 11208 bytes
SHA-256: 7fa9a325f755b1cb225a7a3b11ae513672a47135cedb0810daa585a7f1157c33
font_01_sfnt_off0000f88a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF88A 19396 bytes
SHA-256: 51afbc58b0caac1bf0596ed594bc924fc6b6f128980ca1584e4464d91ee90c6f
font_02_sfnt_off00012c14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1