Malicious PDF — malware analysis report

Static analysis result for SHA-256 26e6a11cbfdcbbec…

MALICIOUS

PDF

36.8 KB Created: 2020-08-31 04:24:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3559c0c43d31c5d52e1a0e1d4ad9575f SHA-1: 1b3eca0a97a0693e7819d669a19e4f0b7a978ca3 SHA-256: 26e6a11cbfdcbbec39d5354361b9dcc53347de1c42ccaae186e89e50391d5d34
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a critical heuristic firing for a malicious redirector link pointing to 'ttraff.ru'. Additionally, it features a mass external PDF link farm, with many links hosted on 'static.usrfiles.com'. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains the same redirector URL. The primary attack vector appears to be luring the user to a malicious site via the embedded link.

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.ru/wix?keyword=star+stable+beginners+guide
    • https://static.usrfiles.com/ugd/b8c837_315e0bff97394a35989d9f9c21f5370a.pdf
    • https://static.usrfiles.com/ugd/b8c837_06dea61e9b6045e2b43814f8eef68f97.pdf
    • https://static.usrfiles.com/ugd/b8c837_aa1d48ee2241479585c769cc68060bd9.pdf
    • https://static.usrfiles.com/ugd/ae059d_2858aea6288a44eeb24da13189d32850.pdf
    • https://static.usrfiles.com/ugd/26938b_d330315694ac44fbb112e6d420a47ba5.pdf
    • https://static.usrfiles.com/ugd/e6092c_e6c082cffd934ea5a1d2f8c248ca9e1e.pdf
    • https://static.usrfiles.com/ugd/affaa6_68c5e01c38ad43c891a17833e4d560f9.pdf
    • https://cdn.shopify.com/s/files/1/0432/3573/7764/files/wosugazedaxerego.pdf
    • https://cdn.shopify.com/s/files/1/0431/7567/4014/files/154234067.pdf
    • https://cdn.shopify.com/s/files/1/0434/0000/3751/files/bescherelle_les_verbes_francais.pdf
    • https://cdn.shopify.com/s/files/1/0428/4982/9023/files/frankenstein_oxford_bookworms.pdf
    • https://cdn.shopify.com/s/files/1/0431/0931/8813/files/solving_quadratic_equations_by_factoring_answers_key.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/jexisobipa.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/

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000045e5.bin
22156189e9eff790716c34058c6d7ffad746b731f51878dd1a9652a78e697cde
pdf-font-stream PDF embedded font (sfnt) at offset 0x45E5 5008 bytes
font_01_sfnt_off000056df.bin
c1d2c32875624efbc7e7ae867425baf43d8a919a7b41d67277f4538eb62dc638
pdf-font-stream PDF embedded font (sfnt) at offset 0x56DF 9788 bytes
font_02_sfnt_off00007826.bin
4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3
pdf-font-stream PDF embedded font (sfnt) at offset 0x7826 4324 bytes