Malicious PDF — malware analysis report

Static analysis result for SHA-256 552df543e5cbe12a…

MALICIOUS

PDF

54.5 KB Created: 2020-08-29 03:25:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-05-09
MD5: c2c9399955d1a7c78e249b4fde949f3b SHA-1: 075186152eed07c6b348ee86abaf6642b5d666d9 SHA-256: 552df543e5cbe12a6c407b4c654100b8390048787c8cc8c891c33946f1c07fc2
194 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link pointing to 'https://ttraff.ru/wix?keyword=python+reinforcement+learning+projects+pdf'. Additionally, it exhibits characteristics of a PDF link farm, with numerous external links, many hosted on 'static.usrfiles.com'. The ML classifier also strongly flagged this PDF as malicious. The primary attack pattern involves luring users to a malicious site via a deceptive link within the document.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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=python+reinforcement+learning+projects+pdf In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://static.usrfiles.com/ugd/b8c837_200f364c922e45bb91bc11556e7d4c61.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_1be7567c9bab474b8c254b8445c7b897.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_273db06355834ebeb9bc3451295e22a3.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_91bf990c28404a6b84c79293ed3236f0.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_b958c538669c433694a6e0ba5b6d0c14.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/4141/4552/files/rifuf.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/0802/4985/files/nubakusudulanagibef.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/3972/7509/files/goludat.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0436/1617/4237/files/free_spreadsheet_programs_for_macbook.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0808/9509/files/critical_thinking_worksheets_for_adults.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0465/0355/9320/files/puvuwisifom.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/5460/4198/files/seloxujebobeke.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_8ddc04b3d3224c8b907a8014768819ca.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_415bde64a0bc42d9af62f05bd185224d.pdfIn PDF document text
    • https://static.usrfiles.com/ugd/b8c837_725656b0a7a34cee9ba910416be135d2.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text
🗂 Part of campaign: cls-asia.net 3 samples

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7110 5536 bytes
SHA-256: 485c91206556c3b6d5baaa324ac86ddc1d34ef4ada4f32085a7c07342b4e9afd
font_01_sfnt_off000083b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x83B0 1952 bytes
SHA-256: 157a80d2d50088e36b2a5e1071e60f2fe9e71d3118812aed6f9bb3bc0a03b7b0
font_02_sfnt_off00008d11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8D11 15384 bytes
SHA-256: 5cd21ad8548ac489f0f389037b3efa65f0e606c6e7965117a94481a16700c6ca
font_03_sfnt_off0000bc65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC65 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3