Malicious PDF — malware analysis report

Static analysis result for SHA-256 94ba4885c348125e…

MALICIOUS

PDF

86.7 KB Created: 2021-05-02 12:29:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 00273302dcdcaf692a5833e28b2ed216 SHA-1: a5cd2726d5d7fb3d5e816853a9b0fe4b6fec4d2a SHA-256: 94ba4885c348125e7ccbc4d8a52fda471f79ef5fcc4056cb19c8d025304760a1
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites, which in turn host other PDF files. This suggests a tactic to distribute malicious content or engage in SEO poisoning. The ML classifier strongly indicated maliciousness, and the structure points towards a multi-stage distribution or redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://saamfactory.com/wp-content/plugins/super-forms/uploads/php/files/782d6d4965c66b687b7b4a60dd19b5e6/13674823690.pdf In PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16087f497cce65---7809831730.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160722cb8e60cf---67737384445.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/98c9084179ee90b9addcc547baaed205/74808713300.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077700845fb0---1885278003.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606eeab773025---78232760336.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/0621f961bc6bfbeb5f09ac2f5fb649d9/72026536645.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/53897ud69n26e8k41eolr87jf5/66464906052.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/hsshrnr23lv2jnlupni3gnkh9v/39808668162.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608604878a449---tebedamejipafumotibes.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/461a38e549243dc94efeff60fc645027/75220857902.pdfIn PDF document text
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/u97s91lh9m6ddcdc85tsquebc1/melajitubovum.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160766e856990f---53989953343.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/a20ss6gsqmpkmsiq10e57mb86v/wufojowesu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=misumi+japan+guidePDF 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC85 10652 bytes
SHA-256: 0402543e37c775fde066aaaffe56050a872ce68cd1b49154dd2c1cf6e9df169d
font_01_sfnt_off0000ff86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF86 5232 bytes
SHA-256: 0a4ea7076cbd872c686ea918efcd86654de3760362ca9b38c36e7d86e1080410
font_02_sfnt_off0001114e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1114E 10488 bytes
SHA-256: 97fd9270c1d4ecbf66d2ea8608201c7a6ada9480d084a845c073e6ed880927de
font_03_sfnt_off00013575.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13575 17004 bytes
SHA-256: 288da54503b86294f929406047c468bf33967a8521671a4cada1b66a6934d3c8