Malicious PDF — malware analysis report

Static analysis result for SHA-256 14bd4b1910290b76…

MALICIOUS

PDF

82.2 KB Created: 2021-09-02 15:13:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 57500177e4645ab847e53519dea9cfce SHA-1: 4acf0939962a793a291bdf35a269247abe0d6303 SHA-256: 14bd4b1910290b7639b26826a211d27b0cd4b71d9e6af2fa987ef2a71960c531
96 Risk Score

Malware Insights

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

The PDF contains a link farm, directing users to multiple external PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The ML classifier strongly indicated maliciousness, and the presence of numerous links suggests an attempt to manipulate search engine results or distribute further malicious content. No scripts were extracted, and the document body was unreadable, limiting the analysis of specific intent beyond link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://sibinetweek.ru/userfiles/file/tolulurusugerepilukapif.pdf In PDF document text
    • http://rallyteamwalraven.nl/file/83278870280.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/280610458395.pdfIn PDF document text
    • http://www.asap-recruitment.net/upload/file/39956263638.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/823mc7mj8eq7vg4ui9dv77a7c2/87216619271.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/1cca45098800a392f9fd80092b0eeeb5/suresagawapowuz.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/2021631011293380.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/botavudiletilipede.pdfIn PDF document text
    • http://ngor2-3.com/file_media/file_image/file/2056893923.pdfIn PDF document text
    • http://autolubitel-irk.ru/userfiles/file/18975900133.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5c554007e---2880500060.pdfIn PDF document text
    • http://proxima-design.cz/files/file/zobojifajeden.pdfIn PDF document text
    • https://fultoys.com/userfiles/duruburujaruzeja.pdfIn PDF document text
    • http://www.heksan.com.pl/file/tesuv.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a38db6548dd---84677586013.pdfIn PDF document text
    • http://phongkhamthienhoa.org/images/files/pipuzudepejefufowukukuxi.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609c6ca9258fc---38356809059.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608655488534f---79607614176.pdfIn PDF document text
    • http://longarmquiltacademy.net/fckeditor/userfiles/file/98895034596.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa6e027c84---sibufelikowudi.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/37356695122.pdfIn PDF document text
    • http://staceyasp.com/UserFiles/file/40904192336.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/86524286463.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=drawing+book+for+beginners+pdfPDF link annotation
    • 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_off0000dc5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC5E 10848 bytes
SHA-256: e69abdf88dba88ce7ddb4c24f20a8f058a94e6dcf34e6635e4e0038d66ae44e2
font_01_sfnt_off0000f529.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF529 17852 bytes
SHA-256: 268675e4d3939130afcad50a1b22e314fcb624fc481c6bea4910d39997ed013d
font_02_sfnt_off000122f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1