Malicious PDF — malware analysis report

Static analysis result for SHA-256 c48935ba771e2b02…

MALICIOUS

PDF

79.5 KB Created: 2021-09-04 20:52:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5241a67f382780ff08b95abcd00e5d4c SHA-1: a980716520b1ccd7a90c1bd2247224f432b9da46 SHA-256: c48935ba771e2b029dd52756cfb1e44a4c67aa445f666bc6cfdc7b92498d32f5
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised CMS uploads and disposable hosting. The embedded URLs likely serve to redirect users to malicious sites, potentially for SEO spam or further exploitation. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://archism.ru/uplcv?utm_term=standard+and+expanded+form+worksheets+2nd+grade PDF link annotation
    • http://www.asap-recruitment.net/upload/file/88049705346.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609a005502e9b---zurerisabopofira.pdfIn PDF document text
    • http://ccsl.asia/files/tedazapigupawavased.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210619184606_v4uuy9.pdfIn PDF document text
    • https://aksusu.com/upload/files/78020159576.pdfIn PDF document text
    • https://fotojursa.cz/userfiles/file/46990746489.pdfIn PDF document text
    • https://cahayamimpi1.com/contents//files/9426407632.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/48645430621.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c1a66f00f66---33922766972.pdfIn PDF document text
    • http://billsky.ee/files/file/28343594338.pdfIn PDF document text
    • https://sanxuattrucauthangkinh.com/Images_upload/files/22077110302.pdfIn PDF document text
    • http://timnhanhonline.net/upload/files/kagudexusufakefu.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608248b511c18---2533368884.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/f1f3aaf80eab142013f24e08eb2fafa0/32184607363.pdfIn PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/wojalefabufavotuvoseviz.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/76355376291.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609667f42f6be---78309658026.pdfIn PDF document text
    • http://cogersquest.com/clients/f/f6/f6194b381802d71b6842d6160e8859b1/File/63146705193.pdfIn PDF document text
    • http://mxag.com/upload/browse/file/84693630989.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/863fbc455c9b772b07dc5471f2ca5213/davazazu.pdfIn PDF document text
    • http://csc0351.com/userfiles/file/20210610143433_e8rwae.pdfIn PDF document text
    • https://caravanandre.it/wp-content/plugins/super-forms/uploads/php/files/98c5c0d8a37208616d1bb6cc7e0844f9/zorawamevureguwaxu.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/kaxijikomimiwukaf.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/pomatamonedubozinepoj.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_off0000d3f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3F2 11284 bytes
SHA-256: 1cc8bb3245c93779402eeb0a38990e7f6a11ef0bc5d18cb12aae687d86e96c9f
font_01_sfnt_off0000ee29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE29 16164 bytes
SHA-256: 76a20c10d3d98bcd4d7a9ace195ecf661b096c82d54fd61fbc1e86212d3d7b77
font_02_sfnt_off000117c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1