Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b165726f89204fa…

MALICIOUS

PDF

33.4 KB Created: 2020-11-06 10:33:19 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 7fd6004aa5958ce3b31ba6e2c17b3f0c SHA-1: e77e5b2481806a1c09676bb2f5784c62e2280220 SHA-256: 2b165726f89204fa51d403073dc71f00d62e093a0cc513721800e6f2a53a4a6b
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to other PDFs, suggesting a link farm or SEO manipulation tactic. One embedded URI, 'https://trafffe.ru/strik?keyword=hannibal+public+schools+mo', is particularly suspicious. The ML classifier strongly indicated maliciousness, and the PDF structure with numerous external links aligns with techniques used to distribute malicious content or engage in SEO spam. No scripts were extracted, but the presence of many external links implies a potential for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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 https://trafffe.ru/strik?keyword=hannibal+public+schools+mo PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4368250/normal_5f89f8f8d0384.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375704/normal_5fa0449f8877e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366317/normal_5f89cd6c5022b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392867/normal_5fa02d8929b4a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406473/normal_5f9a4d04bba3d.pdfIn PDF document text
    • https://vuxozajuje.weebly.com/uploads/1/3/1/3/131379873/1867598.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368248/normal_5f9414d264ced.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370777/normal_5f88b6e6aed89.pdfIn PDF document text
    • https://jeretidaker.weebly.com/uploads/1/3/4/5/134595905/vefuwuniwamuti_zunatarudefez.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375704/normal_5f9780d241330.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000046e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x46E8 5180 bytes
SHA-256: 62e4501162c8896437c8c9633709b6e11d7445c32d041fb32af2ea2ebbcb7b87
font_01_sfnt_off00005855.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5855 9676 bytes
SHA-256: b79e80b1a6af27c7f7ac7fcf0b691f1c18bd5d4ea6a4ff1ba8aa0b7763208ef4