Malicious PDF — malware analysis report

Static analysis result for SHA-256 88ebba4c6e11d043…

MALICIOUS

PDF

42.2 KB Created: 2020-08-20 00:26:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d6c6f58d7fffbba61dacd757c42205f7 SHA-1: 565d512bf82a78980aa0e60d562c739c592d987d SHA-256: 88ebba4c6e11d0433c25e53cbb43d6de5e93ad0468ad5516607d0fb661ba2b78
154 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating it links to known malicious redirector infrastructure. It also exhibits characteristics of a PDF link farm, with numerous external links, some of which are to benign Shopify domains but others are to unknown or potentially malicious sites. The document body, though heavily obfuscated, contains a URL that matches the malicious redirector.

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=epileptiform+activity+in+the+brain
    • http://files.argumentcritique.com/uploads/1/3/1/3/131398212/889ee5bbeaa317.pdf
    • http://files.olsyouth.com/uploads/1/3/1/4/131453588/7916754.pdf
    • http://kunupunus.rescuedfirewood.com/uploads/1/3/1/3/131383541/3829052.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0440/5755/9190/files/esab_mig_master_250.pdf
    • https://cdn.shopify.com/s/files/1/0438/6629/2389/files/84613252923.pdf
    • https://cdn.shopify.com/s/files/1/0434/1596/1762/files/82638884448.pdf
    • https://cdn.shopify.com/s/files/1/0435/9615/2995/files/data_structures_and_algorithms_in_python_wiley.pdf
    • http://files.mkumar.people.ua.edu/uploads/1/3/1/4/131437984/kaxogodevusume.pdf
    • https://cdn.shopify.com/s/files/1/0433/4272/5275/files/sample_sale_los_angeles_2016.pdf
    • https://cdn.shopify.com/s/files/1/0430/7527/2855/files/file_bitmap_gratis.pdf
    • https://cdn.shopify.com/s/files/1/0429/7405/2503/files/64263636803.pdf
    • https://cdn.shopify.com/s/files/1/0437/6382/6849/files/6626432280.pdf
    • https://cdn.shopify.com/s/files/1/0436/0765/4563/files/ludekaziwedilulejikusibez.pdf
    • https://cdn.shopify.com/s/files/1/0431/6450/0122/files/jadasiwofuvebuxaloleruxid.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006798.bin
b369ed81f8b40b765478736817fb9a8ce5a24a8b2b475429ad5672a23e83ecf5
pdf-font-stream PDF embedded font (sfnt) at offset 0x6798 5336 bytes
font_01_sfnt_off000079a2.bin
34180fb018b4286aecc864c0d8e2a014546c0cd0e78ea2fc7bf9e593ee567805
pdf-font-stream PDF embedded font (sfnt) at offset 0x79A2 10060 bytes