Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a76569277c7283e…

MALICIOUS

PDF

40.5 KB Created: 2020-08-14 20:30:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 426b42b400fede33b52979b234c5052a SHA-1: 04dc9f8d8e685535c4e09b913781b797a7f701c6 SHA-256: 0a76569277c7283e35330badc4cb0ae3a86434a4df15271f0e1081737084ce8c
154 Risk Score

Malware Insights

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

The PDF contains embedded links that lead to a malicious redirector, disguised as a vocabulary workshop answer key. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK confirms the malicious nature of the primary URL. The document body, though heavily obfuscated, contains the primary malicious URL and several other PDF links, suggesting a link farm or redirection strategy. No scripts were extracted, but the presence of embedded URLs and the ML classification strongly indicate a malicious intent to redirect users to harmful content.

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://ttraff.cc/wb?keyword=vocabulary%20workshop%20level%20c%20answers%20pdf
    • http://files.ronellesart.com/uploads/1/3/2/7/132740682/2469458.pdf
    • http://files.uainsectcollection.com/uploads/1/3/1/3/131398598/2519af41e236.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0441/3207/3624/files/vatuxadaku.pdf
    • https://cdn.shopify.com/s/files/1/0440/4068/3685/files/9626998294.pdf
    • https://cdn.shopify.com/s/files/1/0429/2601/4620/files/silenolufuri.pdf
    • https://cdn.shopify.com/s/files/1/0427/4647/8759/files/lakojifov.pdf
    • https://cdn.shopify.com/s/files/1/0428/7512/5919/files/business_management_syllabus_ib.pdf
    • https://cdn.shopify.com/s/files/1/0430/0469/0581/files/tojupapelipaji.pdf
    • https://cdn.shopify.com/s/files/1/0436/3865/3086/files/28166915955.pdf
    • https://cdn.shopify.com/s/files/1/0440/2357/8774/files/mejugoforivosunu.pdf
    • https://cdn.shopify.com/s/files/1/0440/9065/4870/files/dilomixizejuwipikile.pdf
    • https://cdn.shopify.com/s/files/1/0435/2524/3039/files/55491569353.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_off00006265.bin
ad17123d15d2195d22ae0d476649d3f1d996b098197fd5e6de07efdcf0106821
pdf-font-stream PDF embedded font (sfnt) at offset 0x6265 5668 bytes
font_01_sfnt_off000075ae.bin
5e61a7b6f673ccf92d1d96a43fa5786c1a5503a20584b012fa6c1ead6165c26d
pdf-font-stream PDF embedded font (sfnt) at offset 0x75AE 9316 bytes