Malicious PDF — malware analysis report

Static analysis result for SHA-256 9743eadf2fee3427…

MALICIOUS

PDF

39.8 KB Created: 2020-08-14 20:43:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 17b3fcc99522ba74c075d6c3393e4127 SHA-1: 2d02f2a72890e580ca99fb58aea7da9cce456d69 SHA-256: 9743eadf2fee3427ec7b6d90c024189fad9e55744786e1abdbb9181d5f0d7637
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains text related to 'worksheets for kindergarten free' and a URL that appears to be part of a link farm designed for SEO manipulation. The ML classifier strongly flagged this PDF as malicious. The primary attack pattern involves luring users to malicious sites via these links.

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=worksheets%20for%20kindergarten%20free
    • http://files.maltron.com/uploads/1/3/1/3/131379296/wezukiwusafapelate.pdf
    • https://cdn.shopify.com/s/files/1/0447/5063/5162/files/g_unit_beg_for_mercy.pdf
    • https://cdn.shopify.com/s/files/1/0437/4223/2725/files/xiwut.pdf
    • https://cdn.shopify.com/s/files/1/0432/7515/7670/files/94930846972.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/86556218032.pdf
    • https://cdn.shopify.com/s/files/1/0437/3266/4481/files/zunokawenip.pdf
    • https://cdn.shopify.com/s/files/1/0430/0174/1463/files/zugobotuliwobutuwuzarigu.pdf
    • https://cdn.shopify.com/s/files/1/0429/6792/4899/files/36974407551.pdf
    • https://cdn.shopify.com/s/files/1/0427/7128/4135/files/universal_self_scorer_biology_book_download.pdf
    • https://cdn.shopify.com/s/files/1/0428/2174/6847/files/71758638768.pdf
    • https://cdn.shopify.com/s/files/1/0429/2182/0319/files/89036636168.pdf
    • https://cdn.shopify.com/s/files/1/0435/7675/4344/files/mizopil.pdf
    • https://cdn.shopify.com/s/files/1/0430/5669/3397/files/2496780669.pdf
    • https://cdn.shopify.com/s/files/1/0436/2996/9561/files/72777967575.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_off00005e9d.bin
c0016a48e325bc93162ca810f7142148a2ba773c4d31d828c1b9782000f8c376
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E9D 5216 bytes
font_01_sfnt_off00007064.bin
007459a9cf660892fdfcc265cfe65373d75e48eb9f17e482c21e3ad35a8927e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x7064 9996 bytes