Malicious PDF — malware analysis report

Static analysis result for SHA-256 bbc134de33b38c8a…

MALICIOUS

PDF

66.3 KB Created: 2021-04-16 04:10:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 988c89a8d60bf54ce888fde5a6e9c9e0 SHA-1: 600d1b77c9a9c4ef2bb3c994ea88e24e6864796c SHA-256: bbc134de33b38c8a213cf1ac06ef8725bc467412fdc364cad38709ade242ce59
66 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to link farms or disposable hosting, indicating a potential distribution mechanism for malicious content. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the PDF structure and embedded URIs suggest an attempt to redirect users to potentially harmful websites.

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 http://oaklandchildcare.org/sites/default/files/webform/ponezilineg.pdf In PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/tuwagamutavuvefofufeniz.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/14219433733.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/97818084314.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/58607877977.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/12404161593.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/rebunedirewe.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/dexifivoneput.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/27999686052.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/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=what+are+basic+math+skillsPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/67925993666.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/zupedofijemurak.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_off0000c782.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC782 5256 bytes
SHA-256: eedc1b1fcec476cc6391c094e24a094e504296b96a6c5018cb4ecf3b8fe43873
font_01_sfnt_off0000d940.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD940 10412 bytes
SHA-256: dac9f888c76810316a2a4f108d139c2056ef269f389c6baffc5dae1df1b469dc