Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a9ce99108d4023b…

MALICIOUS

PDF

45.3 KB Created: 2020-08-14 21:17:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0b164bd88054a71833232959117eea45 SHA-1: 30bd6f79fab01d6f1f15be3ab8f0e813b0a46911 SHA-256: 8a9ce99108d4023b152ac794f2c5dfea0e9ce9c5d20121060f7ec1c4eb59581f
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains embedded links, with one pointing to a known malicious redirector at 'https://ttraff.ru/wb?keyword=text%20to%20pdf%20converter%20app'. The document body, though heavily obfuscated, also contains references to 'text to pdf converter app' and URLs, reinforcing the lure. The presence of a large number of external PDF links, many hosted on Shopify, suggests a link farm or SEO poisoning tactic to increase visibility. The ML classifier strongly flagged this PDF as malicious.

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/wb?keyword=text%20to%20pdf%20converter%20app
    • http://files.envirolaser.com/uploads/1/3/0/8/130814515/susok.pdf
    • https://cdn.shopify.com/s/files/1/0428/8705/3471/files/70685939584.pdf
    • https://cdn.shopify.com/s/files/1/0429/8270/3257/files/dotidotesoxuvoxom.pdf
    • https://cdn.shopify.com/s/files/1/0434/8238/2502/files/37099994268.pdf
    • https://cdn.shopify.com/s/files/1/0432/9085/3534/files/borges_book_of_imaginary_beings.pdf
    • https://cdn.shopify.com/s/files/1/0433/6150/1336/files/tofoduguvolojigamizelijo.pdf
    • https://cdn.shopify.com/s/files/1/0432/3885/0728/files/25495482881.pdf
    • https://cdn.shopify.com/s/files/1/0448/1702/3138/files/carmina_burana_orchestral_parts.pdf
    • https://cdn.shopify.com/s/files/1/0427/9032/2342/files/agile_project_management_download.pdf
    • https://cdn.shopify.com/s/files/1/0429/2640/7833/files/organic_chemistry_wade_8th_edition_download.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006efe.bin
26681f1a12ed3d23752ded16226c7dfe555fa68b305b6695bfbd18efaafeffeb
pdf-font-stream PDF embedded font (sfnt) at offset 0x6EFE 5016 bytes
font_01_sfnt_off00008029.bin
b57bd4af2abbd87b6775f43eb8e6a44c51584ffd826ecb293f9878316283159f
pdf-font-stream PDF embedded font (sfnt) at offset 0x8029 12552 bytes