Malicious PDF — malware analysis report

Static analysis result for SHA-256 8781094b98616658…

MALICIOUS

PDF

56.9 KB Created: 2020-08-30 03:15:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 52a9a84ad84471da58ca854f4e337a03 SHA-1: 8ab1f2aa1ee9a7931cbce6eef2132f84a702df5c SHA-256: 8781094b98616658f37a09b0c5fd56b0394e1951989e6080a6c9e233d6077370
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with one identified as a malicious redirector. The document body, though heavily obfuscated, includes text related to 'restrictive and nonrestrictive clauses exercises with answers pdf' and the malicious URL itself, suggesting a lure for SEO spam or phishing. The ML classifier also strongly indicated maliciousness.

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.com/wix?keyword=restrictive+and+nonrestrictive+clauses+exercises+with+answers+pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/8d57bd_3adf3cf2759e48c5a16fa964da6cc935.pdf
    • https://static.usrfiles.com/ugd/c068f8_e63de04266924575aa154f3338c653ef.pdf
    • https://static.usrfiles.com/ugd/6cf0f5_e4913e9d06d5421687c7de39c9232ad1.pdf
    • https://static.usrfiles.com/ugd/b5472a_b9a456e71e4f4dd3b1fa827276b6165f.pdf
    • https://cdn.shopify.com/s/files/1/0440/3258/9989/files/93170894421.pdf
    • https://cdn.shopify.com/s/files/1/0439/7573/7502/files/rezusugumide.pdf
    • https://cdn.shopify.com/s/files/1/0433/1044/8795/files/datukogefemi.pdf
    • https://cdn.shopify.com/s/files/1/0431/0417/4233/files/transformation_and_articulation_of_form.pdf
    • https://cdn.shopify.com/s/files/1/0431/9582/6336/files/fuvumafelet.pdf
    • https://cdn.shopify.com/s/files/1/0434/7687/7478/files/velozes_e_furiosos_7_filme_completo_dublado_mega_cine.pdf
    • https://cdn.shopify.com/s/files/1/0440/5359/4277/files/11941443225.pdf
    • https://static.usrfiles.com/ugd/badafb_5fb6e08cddea4d9e9af93e8bdfb30806.pdf
    • https://static.usrfiles.com/ugd/49be48_3a402ebbdc844f2ba303b700d2620194.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00009449.bin
4aba2bb845853324476be69e5ed1bf4ff35002942389efac2b843cac1129f0e9
pdf-font-stream PDF embedded font (sfnt) at offset 0x9449 2828 bytes
font_01_sfnt_off00009e44.bin
1b23865afbb5d6b26f3e6ef8817f6186be4dcf787e1780a787703750719970b5
pdf-font-stream PDF embedded font (sfnt) at offset 0x9E44 5472 bytes
font_02_sfnt_off0000b0f4.bin
8563702ae359d8047f270fa641b39f24e6de3db6d9e22713e4b66c492c4df640
pdf-font-stream PDF embedded font (sfnt) at offset 0xB0F4 10096 bytes