Malicious PDF — malware analysis report

Static analysis result for SHA-256 a52eec654a712d1d…

MALICIOUS

PDF

50.9 KB Created: 2020-11-08 22:35:48 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8c02f10c66a111a5eb1c0df9dd5acfcd SHA-1: 5e83cc42907038f31b8b229b62481da4813ce1b5 SHA-256: a52eec654a712d1d4bb0c6fac3ed5f9bdb6954cbd62bac575790f4242d99d615
154 Risk Score

Malware Insights

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

The PDF contains numerous links, including one pointing to a known malicious redirector. The document body, though heavily obfuscated, contains a URL that appears to be part of a link farm designed to attract traffic. The ML classifier strongly indicates maliciousness, and the PDF structure suggests it's designed to host and distribute external links.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://cctraff.ru/123?keyword=animal+classification+worksheets+for+kids
    • https://robubafo.weebly.com/uploads/1/3/4/5/134588337/giwukibanijet.pdf
    • https://xojisige.weebly.com/uploads/1/3/1/6/131637148/deriginop-fagolukizi.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/c6d096bc-37a9-4b82-8bd7-e861235b9245/40165715537.pdf
    • https://s3.amazonaws.com/henghuili-files2/vitigedejekezadewanig.pdf
    • https://uploads.strikinglycdn.com/files/05554e5e-c48f-43aa-aee8-972ac9834f21/39498773235.pdf
    • https://uploads.strikinglycdn.com/files/1bbf6152-c0e8-4dff-9e99-bbcddef84129/pakobozadotewowobako.pdf
    • https://uploads.strikinglycdn.com/files/993e31b8-4d5a-4b2a-963a-288f122a41df/24926567864.pdf
    • https://uploads.strikinglycdn.com/files/e12124be-5df5-4f75-bed5-32453f0a4965/94888866723.pdf
    • https://s3.amazonaws.com/rovikibixu/wrinklers_cookie_clicker.pdf
    • https://uploads.strikinglycdn.com/files/eaab4b68-ab09-4592-b102-f191063d7b9c/58595218638.pdf
    • https://s3.amazonaws.com/bifamomove/unit_1_progress_check_mcq_answers_calculus.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_off00008963.bin
8aa99bbc002b9a8184eab02b6a7247dd319ef76a3c4a137596c31fa03973306b
pdf-font-stream PDF embedded font (sfnt) at offset 0x8963 5404 bytes
font_01_sfnt_off00009ba4.bin
33249b36de3921223ea161c36de114e3f40fb14084337dc1898b84e9e4c55bf2
pdf-font-stream PDF embedded font (sfnt) at offset 0x9BA4 10240 bytes