Malicious PDF — malware analysis report

Static analysis result for SHA-256 418dcb243c1ccda1…

MALICIOUS

PDF

72.7 KB Created: 2021-09-02 06:59:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2310430a5b87f99b517f2c51561ab6d4 SHA-1: 110aae1496d2ecb673e390579ad662b2a5f78066 SHA-256: 418dcb243c1ccda145e869ad8013803af89054b3e4939b9d00d7d9c201e77cbf
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or are hosted on disposable domains, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://pistant.ru/uplcv?utm_term=does+a+90+degree+wash+shrink+clothes PDF link annotation
    • http://sdds.be/userfiles/file/lekugijikuriwawoza.pdfIn PDF document text
    • http://hurtmar.pl/Upload/file/84067784903.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa53a0a3b3---zewukenovusedifavidawu.pdfIn PDF document text
    • https://x-software.cz/data/file/disenapituragudatafera.pdfIn PDF document text
    • http://elverum-revmatiker.no/images/file/91387137343.pdfIn PDF document text
    • http://orderkai.com/uploads/files/vididodosizixusera.pdfIn PDF document text
    • https://cyklo-wellness-penzion-palice.cz/content/3711185182.pdfIn PDF document text
    • http://oticonshop.com/ckfinder/userfiles/files/11278009872.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b74f51577---81870428041.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1608771c357e93---zonogisa.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/1668975051.pdfIn PDF document text
    • http://ntiverification.com/userfiles/file/44814459978.pdfIn PDF document text
    • https://asset-books.com/userfiles/file/35974993624.pdfIn PDF document text
    • http://centrons.com/uploaded/file/17263233106111600cb9def.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e53b657a5---47702326324.pdfIn PDF document text
    • http://bassbasement.org/userfiles/file/bojakikazaparukebisiji.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/7d0a90c320da2c9ed337e75e6ef8d87f/87318201963.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/160909084efa7a---69364412108.pdfIn PDF document text
    • http://brette-animation.com/userfiles/file/tigimu.pdfIn PDF document text
    • https://myparrotfood.com/user_files/files/movefofotivi.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_off0000b8b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8B5 16792 bytes
SHA-256: 83eec1f38461d16e15a2a564851e034cffa938ca52bd5ffb9b27b80cdc864d69
font_01_sfnt_off0000e3e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E4 11120 bytes
SHA-256: 8ee994bcd228cede08f060560e072076847919656b40781590d50a3d448e5e48
font_02_sfnt_off0000fdaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1