Malicious PDF — malware analysis report

Static analysis result for SHA-256 5845ca9400f4e6f0…

MALICIOUS

PDF

63.9 KB Created: 2020-11-23 02:32:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ee5c870f960e3600c4cbd0ac054ad2ad SHA-1: d1d27a4553d90b6c5bc42e0f4d8e56a50a647997 SHA-256: 5845ca9400f4e6f0bff10301d1d72a0ecf90a88c64b49bb6d227953957c13fa7
96 Risk Score

Malware Insights

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

The PDF file contains numerous external links, a technique often used for SEO spam or to redirect users to malicious sites. The ML classifier strongly indicates maliciousness. While no scripts were directly extracted, the PDF structure and embedded URIs suggest an attempt to drive traffic to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://trafficel.ru/123?utm_term=coin+toss+probability+worksheet
    • https://cdn-cms.f-static.net/uploads/4408188/normal_5f95a53b61bbb.pdf
    • https://cdn-cms.f-static.net/uploads/4366343/normal_5f888b90941be.pdf
    • https://sibakixode.weebly.com/uploads/1/3/2/8/132814768/6c71955787.pdf
    • https://cdn-cms.f-static.net/uploads/4378378/normal_5f90e56d8cae4.pdf
    • https://cdn-cms.f-static.net/uploads/4381529/normal_5f9f6350da1c1.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/0e5794b8-c0c7-4776-a894-f34dc7bc43c0/74267867553.pdf
    • https://uploads.strikinglycdn.com/files/d0b582da-db52-4a02-9a8c-73859eedee55/pomorutawajopegubab.pdf
    • https://uploads.strikinglycdn.com/files/fc3c0e05-238d-4c23-8cda-4193d065cd18/73545792213.pdf
    • https://uploads.strikinglycdn.com/files/eae273a3-9ea0-4458-b618-23300ba366ec/61051878254.pdf
    • https://uploads.strikinglycdn.com/files/e3e35980-a3b6-43da-ae22-05ce97a4ef89/58703615054.pdf
    • https://uploads.strikinglycdn.com/files/665bfc18-7315-4e29-ab40-b09c0fe7dc83/xozazaleg.pdf
    • https://uploads.strikinglycdn.com/files/ca907bbe-8818-4823-8f25-477142b90e11/34401244906.pdf
    • https://uploads.strikinglycdn.com/files/69887145-84c1-46c0-800b-0f53b35ac657/mifikuzisaludebolop.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bcbe.bin
76600748fb1ea66cfbb7eab48dbab6e3165661571f0aae10e4733a250b01d670
pdf-font-stream PDF embedded font (sfnt) at offset 0xBCBE 5208 bytes
font_01_sfnt_off0000ce7a.bin
b31354a40a2375b257d65745408c93bd230d7eecafc918ee33da17817c0a8942
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE7A 10772 bytes