Malicious PDF — malware analysis report

Static analysis result for SHA-256 c236ed4a906ec557…

MALICIOUS

PDF

39.8 KB Created: 2020-08-11 21:55:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1c162c793bcd30612aac349be08ed733 SHA-1: 1457edd3345e1bbaaea8f2d74952818609ef3ea5 SHA-256: c236ed4a906ec557c77f72d78d3ae8c11588f340af5e59428e8cf2c70783f9a6
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to Shopify domains, but one critical link directs to a known malicious redirector at ttraff.ru. The document body, though heavily obfuscated, contains the same malicious URL and a benign-looking title related to student learning, suggesting a lure. The ML classifier strongly flagged this PDF as malicious, and the presence of a redirector link indicates a likely attempt to deliver a secondary payload or lead the user to a phishing 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/wb?keyword=student%20enthusiasm%20for%20learning%20pdf
    • http://files.lucretiabingham.net/uploads/1/3/0/7/130775737/binedimeked.pdf
    • http://majumeme.savajrsvolleyball.com/uploads/1/3/0/9/130969060/1715516.pdf
    • http://files.cityskyflooring.com/uploads/1/3/1/4/131437484/8717682.pdf
    • https://cdn.shopify.com/s/files/1/0431/6289/4495/files/nesovavipe.pdf
    • https://cdn.shopify.com/s/files/1/0432/0742/6216/files/92543298785.pdf
    • https://cdn.shopify.com/s/files/1/0428/8220/3801/files/54856883134.pdf
    • https://cdn.shopify.com/s/files/1/0434/0324/7781/files/70620014478.pdf
    • https://cdn.shopify.com/s/files/1/0431/9028/8535/files/birijatikiwuzaxede.pdf
    • https://cdn.shopify.com/s/files/1/0441/2165/3400/files/79887385312.pdf
    • https://cdn.shopify.com/s/files/1/0434/2729/9478/files/38337934346.pdf
    • https://cdn.shopify.com/s/files/1/0431/1479/1069/files/xixija.pdf
    • https://cdn.shopify.com/s/files/1/0430/2408/9242/files/55103962609.pdf
    • https://cdn.shopify.com/s/files/1/0434/5511/9520/files/wamobirale.pdf
    • https://cdn.shopify.com/s/files/1/0428/5064/8223/files/92320769716.pdf
    • https://cdn.shopify.com/s/files/1/0434/5469/3537/files/peguwiles.pdf
    • https://cdn.shopify.com/s/files/1/0440/6666/8694/files/nenimusajumal.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_off00005b65.bin
cc10191e9fc164fc0523c35a4a86da4aab7bd37cd54c15fe7e32dbf0f38e5802
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B65 5560 bytes
font_01_sfnt_off00006e1a.bin
a715cb33c499078415a7ce5b14b0b913368191c6f3304ebed652a797be4f6dc4
pdf-font-stream PDF embedded font (sfnt) at offset 0x6E1A 10192 bytes