Malicious PDF — malware analysis report

Static analysis result for SHA-256 a384e4431da18f10…

MALICIOUS

PDF

126.8 KB Created: 2021-07-02 06:56:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 6143c70adc8790ec8f5461596c05482c SHA-1: 1acba6b73212a4f6a266c3d7d8dd563433c7bc10 SHA-256: a384e4431da18f10fa844fe00dd434ea39a7376ce95a233ba91436428df2257b
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs pointing to compromised CMS uploads and disposable hosting domains. This suggests the document is designed to act as a link farm, potentially for SEO manipulation or to redirect users to malicious sites. The ML classifier strongly supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://synerhu.ru/uplcv?utm_term=mumford+and+sons+elvis+costello PDF link annotation
    • http://sh-ruiyangcpa.com/userfiles/file/2021-6///2021626735178859.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607852fd3ff26---jumejonodibabajonatimis.pdfIn PDF document text
    • https://aymsoft.us/aym_image/files/44082944725.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/98cpkenubrei8ec1g15mgni3ll/24364594945.pdfIn PDF document text
    • https://burstallconrad.com/editor_files/file/pisijefalufakizudopu.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607046fa724d9---91922994995.pdfIn PDF document text
    • https://zold-kommando.hu/files/38094911563.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/ba7141d0eb097c0d290488d646a7b27c/gotobonazejowepuranevone.pdfIn PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-5-6/20210506214851142697.pdfIn PDF document text
    • http://montaze.org/democms/userfiles/file/suvovowikeweremadav.pdfIn PDF document text
    • http://efuegypt.org/userfiles/file/nitagaxanawigojipi.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a3bd13845b9---fekoxiritomidumimodiduril.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/4kbg8gqc2cafb7dghb043m4e87/davirabanad.pdfIn PDF document text
    • https://binarbaidfabrication.com/public_html/userfiles/file/gefufojodozena.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16086b73119b87---kexuji.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160924cc0a876b---jajaxubugu.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607cb97ca5384---mazud.pdfIn PDF document text
    • http://www.mediagrand.hu//data/editorfile/vilovajuvividixurax.pdfIn PDF document text
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ccb40c74a4---80437728741.pdfIn PDF document text
    • http://capri.lt/userfiles/files/15929217930.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/160890cc80189c---pifegerewi.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210618024325.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/filefawamixewazepejani.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_off00018a19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18A19 20284 bytes
SHA-256: 9ae4361fd83ef8798378d826aa481c579d7734d3205d7477132f3d8e965524e3
font_01_sfnt_off0001bd37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BD37 10796 bytes
SHA-256: f5bd1a337d1ad8fda05e1ef5a9f8d5a32d956ce6c87e4a5b04f806573cfce418
font_02_sfnt_off0001d61a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D61A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1