Malicious PDF — malware analysis report

Static analysis result for SHA-256 f35688a674601ae5…

MALICIOUS

PDF

74.4 KB Created: 2021-09-05 10:00:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3e3a2fc3ae6f70a6c111985edd99e4a7 SHA-1: a8c14a42d5ba3370d72c1532f226c7dcb7d1c744 SHA-256: f35688a674601ae5e89b566aee1aea6ab2c531f197440df4c855b349421ac87f
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous compromised websites, many of which host other PDF files. This suggests a campaign aimed at SEO poisoning or directing users to malicious content. The ML classifier strongly indicated maliciousness, and the presence of multiple links to potentially compromised CMS upload directories reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://lyzebrno.cz/userfiles/file/tifawugeliketuxobiz.pdf In PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/e115855dd0f71eb9cddbb0228b412f24/50635510075.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/99b9e1b1e640d15616b801ef2d4f5dea/70635755965.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/14977654159.pdfIn PDF document text
    • http://geluidsadviesnederland.nl/ckfinder/userfiles/files/wunojabumanasibavubujez.pdfIn PDF document text
    • https://kmkmekanik.com/upload/ckfinder/files/wufawefusiwiludevubinipu.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/c488f629e7bdf5a41ec708ca57cff83d/vagofotovevip.pdfIn PDF document text
    • https://nffcd.org/userfiles/files/74544371375.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/18308600159.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/160774c79b14db---16336390460.pdfIn PDF document text
    • http://scoutpate.com/userfiles/file/polepekeranidupof.pdfIn PDF document text
    • https://kclandscapes.com/ckfinder/triplebuserfiles/file/pinokowunosodapud.pdfIn PDF document text
    • http://nw-line.ru/generic/uploaded/likumugeb.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c197cea1b2---40125473812.pdfIn PDF document text
    • http://globalsocialwlefaresummit.com//app/webroot/uploads/ckuploads/files/31783765407.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609fe6dfb6d54---jisubajupexu.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/41521176995.pdfIn PDF document text
    • http://contextuae.com/resimler/files/36568242848.pdfIn PDF document text
    • http://saatgaamkansarasamaj.com/admin/uploads/files/sevikadedegufogekagofov.pdfIn PDF document text
    • https://hfdjet.com/wp-content/plugins/super-forms/uploads/php/files/a0df68075bad73a44bef6223b728e53f/25951012277.pdfIn PDF document text
    • http://thepokeluau.com/uploads/files/31823184708.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=ayatul+kursi+pdf+bohraPDF 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_off0000bca0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCA0 18280 bytes
SHA-256: 85dcf8c414807b7ac583fd5aac22992bd8c41d9c721fbdb3eb68f0755fcf90b4
font_01_sfnt_off0000ebec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEC 10788 bytes
SHA-256: 25d9169c8f0f1f555da31465ce8d8df1ca255345d3a04fdc754bd710968faa32
font_02_sfnt_off000104ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1