Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f3b756a948d5f42…

MALICIOUS

PDF

73.1 KB Created: 2021-04-07 02:52:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 011489e15433a42f6e439141ccde72e9 SHA-1: 1412d297fcddfa94c0b52e946e792b54d9636c5c SHA-256: 3f3b756a948d5f42e632bebacd7a37f72da4bd14e768d334613fd64a26721472
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many pointing to domains that appear to be part of a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier strongly flagged this PDF as malicious. The presence of multiple external URIs suggests an attempt to redirect the user to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 4

  • 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://www.uts.cw/sites/default/files/webform/pugixenarewowu.pdf In PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/88462653206.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/40110328039.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/lolavojirubopikumu.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/nikosomonebazi.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/pifudolaloxafedotodela.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/77861868930.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/sakobonomoduriv.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/xufatonapa.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/32041770382.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/jizexatunurometubukos.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/keborezuvefubivuw.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/bunovodedodasu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=annotation+guide+pdfPDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/nufimogunuzin.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/43319512550.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e21e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21E 4892 bytes
SHA-256: f35f26a8b8add034671647f3b5bcfe32ff0a2214d7bc2a5844a1725c06d706b6
font_01_sfnt_off0000f2df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DF 10852 bytes
SHA-256: 262a190c23ea827587a9ae5052610a8bd3d626c6fe8c6618523d3a1d42815a69