Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf9c2089259b8d03…

MALICIOUS

PDF

34.2 KB Created: 2020-08-30 07:50:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e06c27a14516d8eda282750a8fdeda2c SHA-1: eef0a927a66eedc33a43620d64cb2f0307da2b15 SHA-256: bf9c2089259b8d03dc1e84122411297c20e844b833fdb5f3a0db40600a1f7fc2
154 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as a search result for 'Amrutha advanced spoken english pdf'. The ML classifier strongly indicated maliciousness. The document body also contains numerous links, many pointing to Shopify, suggesting a link farm or SEO manipulation tactic to distribute the malicious URL. The primary malicious IOC is the redirector URL.

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=amrutha+advanced+spoken+english+pdf
    • https://cdn.shopify.com/s/files/1/0430/7727/1706/files/32124007508.pdf
    • https://cdn.shopify.com/s/files/1/0430/3929/3593/files/37253510177.pdf
    • https://cdn.shopify.com/s/files/1/0432/2515/3698/files/analytical_and_numerical_methods_for_volterra_equations.pdf
    • https://cdn.shopify.com/s/files/1/0431/8163/7794/files/lidotibedevibevazevizipu.pdf
    • https://static.usrfiles.com/ugd/b8c837_67869d0b1a424653b7b6877be0e9f2df.pdf
    • https://static.usrfiles.com/ugd/b8c837_7c92dc5782b14e0b80868bdc27535de6.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/xidab.pdf
    • https://cdn.shopify.com/s/files/1/0430/0954/0257/files/auditing_assurance_services_a_systematic_approach_11th_edition.pdf
    • https://cdn.shopify.com/s/files/1/0433/8565/1358/files/ielts_academic_reading_papers_with_answers.pdf
    • https://cdn.shopify.com/s/files/1/0430/4034/2169/files/esc_guideline_heart_failure_2016.pdf
    • https://cdn.shopify.com/s/files/1/0434/9722/6402/files/rovibal.pdf
    • https://cdn.shopify.com/s/files/1/0433/4924/6102/files/illustrator_logo_template_file.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_off00004788.bin
0991974c838ebaee29f2243338dde79499ebd3d2b1c6e22d8edc5e023afcdaea
pdf-font-stream PDF embedded font (sfnt) at offset 0x4788 5680 bytes
font_01_sfnt_off00005ab7.bin
87c766a56dca441b6328e6864e59c0ccadf5bc337083831dca641265d1540951
pdf-font-stream PDF embedded font (sfnt) at offset 0x5AB7 9712 bytes