Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8189b8f21f9600e…

MALICIOUS

PDF

33.9 KB Created: 2020-08-21 23:56:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f324a7aad32b69097cee5ccdec35f7c7 SHA-1: 345389e87f486b5cfda7a0e9bb57e1ea712814c2 SHA-256: d8189b8f21f9600e1440197a7e397f9d3f040eb7a1d29b4d305a37aee5c4e27e
152 Risk Score

Malware Insights

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

The PDF contains a heuristic firing for a malicious redirector link, specifically pointing to 'https://ttraff.cc/pify?keyword=advanced+english+proficiency+test+pdf'. It also exhibits characteristics of a PDF link farm, with numerous embedded links to external PDFs, many hosted on Shopify. The ML classifier strongly flagged this PDF as malicious. The document body, though heavily corrupted, contains the same lure text and URLs found in the heuristics, reinforcing the attack pattern.

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.cc/pify?keyword=advanced+english+proficiency+test+pdf
    • http://files.missjusticeart.com/uploads/1/3/1/4/131410009/gosoxidivesusa_fokuginokesobat_gofopupajume.pdf
    • http://files.getnoticedartdesigns.com/uploads/1/3/1/4/131437680/249118.pdf
    • https://cdn.shopify.com/s/files/1/0432/9055/8622/files/safasipegekujewaxikin.pdf
    • https://cdn.shopify.com/s/files/1/0432/8220/2782/files/22049213967.pdf
    • https://cdn.shopify.com/s/files/1/0435/4388/8023/files/bivupedukelalelu.pdf
    • https://cdn.shopify.com/s/files/1/0441/4029/8392/files/98733886781.pdf
    • https://cdn.shopify.com/s/files/1/0435/5905/9615/files/history_research_paper_outline_template.pdf
    • https://cdn.shopify.com/s/files/1/0434/1694/4807/files/22557181941.pdf
    • https://cdn.shopify.com/s/files/1/0432/3786/7687/files/mugipepubuzeni.pdf
    • https://cdn.shopify.com/s/files/1/0435/7062/6723/files/bernardine_evaristo_girl_woman_other.pdf
    • https://cdn.shopify.com/s/files/1/0431/0525/5577/files/jekomosopofuzunafikebifu.pdf
    • https://cdn.shopify.com/s/files/1/0431/3923/5997/files/subesekuz.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_off0000466e.bin
35cca1126a3c0d93d9cb0b77626db103251564d7defd670a601a65f707b245c2
pdf-font-stream PDF embedded font (sfnt) at offset 0x466E 5568 bytes
font_01_sfnt_off00005961.bin
ce6a17a7980a007a8bb68b830481fc33aba28160e546accaa1c5a0190153f11f
pdf-font-stream PDF embedded font (sfnt) at offset 0x5961 9872 bytes