Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa73fed581dc88a0…

MALICIOUS

PDF

53.1 KB Created: 2020-05-26 12:43:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-24
MD5: b13c84447809151dd0be105d4f2f1dbd SHA-1: 26c17da215e1e22a2a1dd03b6750619efd22c9ab SHA-256: fa73fed581dc88a0168b619accec3d414fa49045c908f6d3e6912ec9c1247af1
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1566.002 Spearphishing Link

The PDF file contains a significant number of external links, identified by the PDF_SEO_LINK_FARM heuristic, pointing to various domains. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains references to 'Being and time epub' and the wkhtmltopdf generator, suggesting a lure to download or view content. The primary purpose appears to be directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://psbf85.org/uploads/1/3/0/7/130740443/130740443.html#being+and+time+epub PDF link annotation
    • http://leleader.net/uploads/1/3/1/4/131406291/8c34b4892.pdfIn PDF document text
    • http://ronksmith.com/uploads/1/3/1/3/131383678/70174405fd2.pdfIn PDF document text
    • http://vps26.pleasingfood.com/uploads/1/3/0/7/130738874/dikofijujage.pdfIn PDF document text
    • http://burakbostancioglu.com/uploads/1/3/0/2/130289171/695faacc24fae65.pdfIn PDF document text
    • http://mail.renuntio.co.uk/uploads/1/3/0/2/130287462/tezelur-nixin-gasiwafazaka-rexanijim.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000a274.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA274 11904 bytes
SHA-256: 36ba0b01d882f7a0f4e8d36277abb43d0a8e18d926fe489258c509db068f8f20