Malicious PDF — malware analysis report

Static analysis result for SHA-256 d6fcb1fd4bf6c9cb…

MALICIOUS

PDF

95.2 KB Created: 2021-09-18 18:46:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 051b7db2be5fff0190ab3b4425745eae SHA-1: 575e2428bf9f2cae6683136473d42c4e6854e4df SHA-256: d6fcb1fd4bf6c9cbe40789ebf9b2a0671041519fec07e8521e00da3673e09056
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external links, many of which point to other PDF files hosted on potentially compromised websites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF is a link farm on disposable hosting, suggesting a tactic to distribute malicious content or traffic. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://vaynhe.com/upload/files/xezonuluw.pdf In PDF document text
    • http://dinskayarealty.ru/media/file/gogenaropu.pdfIn PDF document text
    • https://darkoyunpin.com/calisma2/files/uploads/31362019341.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/55835883611.pdfIn PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/falojumekel.pdfIn PDF document text
    • http://easyliveconstruction.com/ci/userfiles/files/witutovopigelisam.pdfIn PDF document text
    • http://jncs.kr/page_data/file/20210909173312.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/bm0m32c78ek6cjmlpk5qgim6mv/pupawofubox.pdfIn PDF document text
    • http://hkwwta.org/userfiles/96244860710.pdfIn PDF document text
    • http://jobcred.com/rk/jobcred/uploads/image/file/82678833797.pdfIn PDF document text
    • http://www.39koratmachinery.com/file_upload/files/wagumosutawal.pdfIn PDF document text
    • http://rialta.ie/userfiles/files/70826104041.pdfIn PDF document text
    • http://jmdfhjl.com/fckeditor/userimages/file/3752344562.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/dulup.pdfIn PDF document text
    • http://xn--42cfa4ewb0a0b3fwh.com/imageupload/files/97434583514.pdfIn PDF document text
    • https://pharma-tools.pl/galeria/file/bikaxedopotelifivad.pdfIn PDF document text
    • https://avistravel.ro/userfiles/file/vimuxaxemomo.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4e9da5efb---44097053278.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/jimowepulogugamo.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613283e176810---kekopel.pdfIn PDF document text
    • https://zerling.eu/nico/images/files/59485732272.pdfIn PDF document text
    • http://mrpokedb.com/uploads/files/84016933446.pdfIn PDF document text
    • http://kristiankutschera.de/userfiles/file/39920092741.pdfIn PDF document text
    • http://stsmcc.org/www/js/ckfinder/userfiles/files/basebubalusafopum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=datepicker+current+datePDF 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_off00011113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11113 17748 bytes
SHA-256: 3daffc61982990bd0538811611ee5a13a203ede0f188d49fe90525163d2ecd9b
font_01_sfnt_off00013fff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FFF 10368 bytes
SHA-256: 99efb843295b11bedf63cf44d780598523a0b267d0c4e25420531efec297685a
font_02_sfnt_off0001578f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1578F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1