Malicious PDF — malware analysis report

Static analysis result for SHA-256 da479f17f228773e…

MALICIOUS

PDF

52.4 KB Created: 2020-08-30 19:48:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e2b9ac089237ea8f9f028ffe9baecbba SHA-1: 2a80b457815a622fe02091525e1143d7fba88510 SHA-256: da479f17f228773eea8cec534120757096809e8b944b9a82fce002930a3f1db7
154 Risk Score

Malware Insights

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

The PDF file contains embedded links, one of which points to a known malicious redirector. The document body, though heavily obfuscated, contains text that appears to be a lure for "USMLE step 1 lecture notes". The heuristic PDF_MALICIOUS_REDIRECTOR_LINK strongly indicates malicious intent, likely to redirect the user to a phishing or malware distribution 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/wix?keyword=usmle+step+1+lecture+notes
    • https://cdn.shopify.com/s/files/1/0436/1686/2371/files/country_list_txt.pdf
    • https://cdn.shopify.com/s/files/1/0427/7311/9143/files/kavukuliwurolatika.pdf
    • https://cdn.shopify.com/s/files/1/0435/8068/6495/files/juzanudugutezi.pdf
    • https://cdn.shopify.com/s/files/1/0436/3508/1374/files/nitazoderojil.pdf
    • https://cdn.shopify.com/s/files/1/0457/5651/4460/files/genetic_variation_in_humans.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/tazoxusejeko.pdf
    • https://cdn.shopify.com/s/files/1/0429/3692/6374/files/50215628219.pdf
    • https://cdn.shopify.com/s/files/1/0434/7723/7920/files/malaria_lab_diagnosis.pdf
    • https://cdn.shopify.com/s/files/1/0431/8468/5224/files/gigiguvuvekatumire.pdf
    • https://cdn.shopify.com/s/files/1/0462/4809/9991/files/98290144145.pdf
    • https://static.usrfiles.com/ugd/b0b521_b095a2ce196a4626b8e53728bf13366c.pdf
    • https://static.usrfiles.com/ugd/b8c837_02e544cf5f764d3da42813614eae20a7.pdf
    • https://static.usrfiles.com/ugd/5fd5c1_084314b56cd44506800786a07d806cc3.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_off00008f09.bin
8f131d6c6c63a33c65475f26288d8ad4462c0217d796e2b61de4e01868a17042
pdf-font-stream PDF embedded font (sfnt) at offset 0x8F09 4912 bytes
font_01_sfnt_off00009fb2.bin
f4c9f09702f7c014b2554e50d8cfe3c8e23ba032e5c43f49f381d9ba925e7df3
pdf-font-stream PDF embedded font (sfnt) at offset 0x9FB2 10816 bytes