Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81bd7df42b557be…

MALICIOUS

PDF

87.2 KB Created: 2021-08-01 10:11:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0dc6bc68d4d988918d3e76c6ce28c9dd SHA-1: 23e041f4dbb0a2a1b41ad01416d50c7b8b1ce18f SHA-256: f81bd7df42b557beb9b69e33fdf8e0bd549d7615f50e85396ae140b67becd745
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs pointing to various compromised websites, many of which appear to be hosted on disposable domains or utilize common CMS vulnerabilities for file uploads. The ML classifier strongly indicated maliciousness, and the presence of link farm heuristics suggests an attempt to manipulate search engine results or redirect users to malicious content. No scripts were extracted, but the overall structure points to a link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608b34b415d8d---84421872048.pdf In PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5cfc0f3d8f---47257170063.pdfIn PDF document text
    • http://fitviewer.biz/files/file/90016467636.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2e9bd1ffbc---67293945041.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/fupox.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/5b7f732d9099d9f0358e739fc0e0d48f/48606817027.pdfIn PDF document text
    • https://noddy.nu/images/file/23550408614.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/806c228f96eb1d602246fb56d2da30e7/11388622033.pdfIn PDF document text
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/m1bq6t08vfucghju4ovoijkcs3/96812759570.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c87aa2060d0---xokuniba.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/eii50gqovfbu6kfve5rfmv48nl/70884258252.pdfIn PDF document text
    • http://kleiberit.ru/files/file/mavumadikepibexe.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/90196822653.pdfIn PDF document text
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/oaehg53jgvtual8bujs9fmfgt0/zapik.pdfIn PDF document text
    • http://bbbswalkforkids.com/clients/c/cf/cf8d0549bdc9bbdffca8bc0db9808b96/File/56307065038.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/4883a673a6af6f5d19ee57de0e4094c1/damigatepurekuf.pdfIn PDF document text
    • http://thedreams.cz/files/dodirotejuxegizovu.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/godixisutuvumexuronaro.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16073298715596---68562035698.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160972b5ce42b3---gewodu.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/5cbdrg1fcnphrnsdgehklt2kj7/zaseworegu.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/vam5lml0uuj5d4060avj78s100/ripese.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=cbse+topper+answer+sheet+2019+class+12+political+sciencePDF 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_off0000ed3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED3E 17196 bytes
SHA-256: 7ee7e320f5e6bfa112b57bef83735f90a6f2c16a4930641776e07c5b0df3ca06
font_01_sfnt_off00011a4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013263.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13263 11188 bytes
SHA-256: affa75de1e0049509fbfa41ce4a78ebb1d58a5e8228db7fe9819372db8cc01fb

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