Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bc7e5c1850dcae0…

MALICIOUS

PDF

42.9 KB Created: 2020-08-31 20:18:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 581a899abee7e5f9f5883a2ca1bf51fd SHA-1: b91c86e3f39d388283f39f20071d1609d64eb127 SHA-256: 5bc7e5c1850dcae0e1ce529ab6c4686015185800534398b4f4c69b20c24dac3a
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded links, many pointing to Shopify domains hosting other PDFs, suggesting a link farm or SEO manipulation tactic. One critical heuristic identified a link to known malicious redirector infrastructure at 'https://ttraff.ru/wix?keyword=vowel+letters+worksheets+for+kindergarten'. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious campaign designed to redirect users to potentially harmful sites.

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=vowel+letters+worksheets+for+kindergarten
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0432/8531/5737/files/bunuwuv.pdf
    • https://cdn.shopify.com/s/files/1/0430/2631/7473/files/47610101821.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/zofoxi.pdf
    • https://static.usrfiles.com/ugd/b9801a_d96c2835fb044a0b948632dcbce73d47.pdf
    • https://static.usrfiles.com/ugd/f63f29_33659f7419004080b0b2dd1df3be996f.pdf
    • https://static.usrfiles.com/ugd/b8c837_c5dee5a90e39463bb8b468e71cefd19f.pdf
    • https://static.usrfiles.com/ugd/3aca14_ecde3484d93e458bb31f3fd3d9b91dc4.pdf
    • https://static.usrfiles.com/ugd/f7fbc8_4d2bb9db04e94dda84797421bee3b0c3.pdf
    • https://static.usrfiles.com/ugd/33c377_4d06b6dc28cf484184f3e33520757a45.pdf
    • https://cdn.shopify.com/s/files/1/0429/4737/9356/files/vector_psd_templates_free.pdf
    • https://cdn.shopify.com/s/files/1/0441/4147/8040/files/77404707184.pdf
    • https://cdn.shopify.com/s/files/1/0454/6687/8102/files/ielts_writing_test_task_1.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_off00006a0a.bin
4993ce1ef76e5b21e88a783cd58b59d5bba8c02ddf0cd166c9b178e724fda524
pdf-font-stream PDF embedded font (sfnt) at offset 0x6A0A 5292 bytes
font_01_sfnt_off00007c18.bin
a5342504cd505c80ec5684c66e0477c26444793123f497e12ca46273c2cfe53a
pdf-font-stream PDF embedded font (sfnt) at offset 0x7C18 10060 bytes