Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2553f827c41cb68…

MALICIOUS

PDF

40.9 KB Created: 2020-09-01 13:22:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 35bf5985bfbe6e1e9256adc82a72cd0a SHA-1: c7d4ab0ea1353aec4a1fb7aac6df883aa80f0395 SHA-256: a2553f827c41cb686ec0280bf6f68a14584e91d9738ffa2f50d4d0bb43007a3e
152 Risk Score

Malware Insights

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

The PDF file contains a critical heuristic firing for a malicious redirector link, pointing to 'ttraff.ru'. The document body, though heavily obfuscated, also contains this URL and numerous other links to PDF files hosted on 'static.usrfiles.com', indicating a link farm strategy. The ML classifier also strongly flagged this PDF as malicious. The primary attack pattern involves 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=johan+cruijff+arena+self+guided+tour
    • https://static.usrfiles.com/ugd/9ea91e_c4eab2c5b3a44b3ba4910056ee1a33e8.pdf
    • https://static.usrfiles.com/ugd/2e16aa_f332c95c68ac4ab2beb470004d7f91b6.pdf
    • https://static.usrfiles.com/ugd/99965f_f65d58df47df4a18a6e1f55d38bca523.pdf
    • https://static.usrfiles.com/ugd/daca0d_8fc5ee2c150a4acdbc627cb30447c711.pdf
    • https://static.usrfiles.com/ugd/b8c837_41739e46bade405d8169c1762424a5e1.pdf
    • https://static.usrfiles.com/ugd/b8c837_d8405a7a87514521a8b6e3a1fa891439.pdf
    • https://static.usrfiles.com/ugd/77941b_d9d4fa914aa645eaa50a95d0d9b29146.pdf
    • https://static.usrfiles.com/ugd/b8c837_d06114fd55c34a168a23eb77a0e2652f.pdf
    • https://cdn.shopify.com/s/files/1/0435/3907/1144/files/rizofamexega.pdf
    • https://cdn.shopify.com/s/files/1/0436/9684/9051/files/71802474803.pdf
    • https://cdn.shopify.com/s/files/1/0445/8446/8644/files/learn_python_for_beginners_download.pdf
    • https://cdn.shopify.com/s/files/1/0429/9459/8047/files/31041317159.pdf
    • https://cdn.shopify.com/s/files/1/0431/8468/5220/files/bisaxodorumojopikakufabi.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_off000061d1.bin
dcd99cd8b3e55e1eab57e8ff9f264cf9202f3f694196a6d71d8679fde65ae16c
pdf-font-stream PDF embedded font (sfnt) at offset 0x61D1 5348 bytes
font_01_sfnt_off000073fd.bin
b09085fff869b8eebe8454ccc9055962923d5982dbc0d5653a75752bcb3ef5a1
pdf-font-stream PDF embedded font (sfnt) at offset 0x73FD 10288 bytes