Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a5e03bc2f3dbe88…

MALICIOUS

PDF

109.8 KB Created: 2020-08-20 22:49:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0e32ee17bf2e585653ac9878cef13aee SHA-1: 69fd7b6538f4507adcc16615582333d730b03881 SHA-256: 8a5e03bc2f3dbe885399b14659804b62a36b6af3b2db328ac2ee7ec159df1961
152 Risk Score

Malware Insights

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

The PDF contains a significant number of embedded links, identified as a link farm. One of these links, 'https://ttraff.ru/pify?keyword=idsa+discitis+guidelines', points to known malicious redirector infrastructure. The ML classifier also strongly indicated maliciousness. The document body itself is heavily obfuscated and contains the malicious URL, suggesting a lure to a malicious site.

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/pify?keyword=idsa+discitis+guidelines
    • http://bavev.sticksandstones1.com/uploads/1/3/0/7/130775934/sivavipulabav.pdf
    • http://files.narrenofnewulm.com/uploads/1/3/2/3/132302819/1d4814a419.pdf
    • https://cdn.shopify.com/s/files/1/0433/2378/5370/files/jidowaduparomazisa.pdf
    • https://cdn.shopify.com/s/files/1/0431/0866/3462/files/medical_fitness_certificate.pdf
    • https://cdn.shopify.com/s/files/1/0432/9432/6942/files/vowuvolevizidanix.pdf
    • https://cdn.shopify.com/s/files/1/0433/9862/7495/files/34904774683.pdf
    • https://cdn.shopify.com/s/files/1/0435/1783/7480/files/zetukunemeba.pdf
    • https://cdn.shopify.com/s/files/1/0432/9085/3541/files/tamil_to_english_words.pdf
    • https://cdn.shopify.com/s/files/1/0454/7464/4120/files/physics_textbook_for_secondary_school.pdf
    • https://cdn.shopify.com/s/files/1/0429/2847/2220/files/zuvafexobu.pdf
    • https://cdn.shopify.com/s/files/1/0436/0355/8564/files/16211269756.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/32177526878.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_off000175a6.bin
4de03068621de994ef45ace1b5fa9480a05d59e4466e696bc468a14332cd5844
pdf-font-stream PDF embedded font (sfnt) at offset 0x175A6 4948 bytes
font_01_sfnt_off00018688.bin
d87037bc5624b79caaec17b837283b6dfeebc4b341b0e55e3e9bd9044453cf25
pdf-font-stream PDF embedded font (sfnt) at offset 0x18688 10404 bytes