Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4c177acaa66f406…

MALICIOUS

PDF

35.2 KB Created: 2020-08-31 01:44:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c6eb757eca5e3efb94b4451a7a9fd113 SHA-1: f6f677e8fd62c413a9b8ca7fc71738745f756a35 SHA-256: f4c177acaa66f406b56996e8c2fef6844e6f53cc6acd95253b14fe8391515da3
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 exhibits characteristics of a PDF link farm, with numerous embedded URLs, many of which resolve to 'static.usrfiles.com'. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains the malicious URL and references to other PDFs, suggesting a lure to external content. The primary attack pattern involves redirecting the user to a malicious site, likely for phishing or to download further malicious 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.ru/wix?keyword=on+cooking+6th+edition+etext+with+my
    • https://static.usrfiles.com/ugd/b8c837_0725ec1cacfc4d5fa647dcaf7a2bfee7.pdf
    • https://static.usrfiles.com/ugd/d162e3_8c477921289440a7ad7e9f08b42c36a9.pdf
    • https://static.usrfiles.com/ugd/b914b5_7dfab37f71ee480687127b9d40cae9dc.pdf
    • https://static.usrfiles.com/ugd/dfb5f8_f9b5d1cecad34dc9810849ca01fa6795.pdf
    • https://static.usrfiles.com/ugd/3ab5ed_bf74f6654e6c488ab4a7c3c31bb87f74.pdf
    • https://static.usrfiles.com/ugd/b8c837_c76d37e2515a4a21b7f32e3888465f3a.pdf
    • https://static.usrfiles.com/ugd/b58d21_8cd96547c1a4475bb9c7366f1f4ac3e3.pdf
    • https://cdn.shopify.com/s/files/1/0432/0359/2353/files/excel_indirect_sheet_name_example.pdf
    • https://cdn.shopify.com/s/files/1/0431/0604/2013/files/vipubirazikir.pdf
    • https://static.usrfiles.com/ugd/122077_76e1e8a1e1274392bfb2c55883459b33.pdf
    • https://static.usrfiles.com/ugd/3bf302_cf0183b116da4d9dad3a159605b0aa25.pdf
    • https://static.usrfiles.com/ugd/b8c837_5b1f34a90f154d6a9ae8453c507d52bf.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_off00004c05.bin
2bb688845768423e34748fffa9cafdf3e089f6b1fb3fb558365b6c703d888906
pdf-font-stream PDF embedded font (sfnt) at offset 0x4C05 5344 bytes
font_01_sfnt_off00005e1b.bin
ad9dc597d9df8bdf7220eb1ac434949a4d9262bbc7beead826adabf7e2a4ca64
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E1B 9896 bytes