Malicious PDF — malware analysis report

Static analysis result for SHA-256 5131d77ee9dbf442…

MALICIOUS

PDF

40.2 KB Created: 2020-08-23 17:21:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 36bc0db599c3fd08e811c509caf1fcc2 SHA-1: 02dad6a70586d8f457684f4b35570438c04e223f SHA-256: 5131d77ee9dbf44205552d1c41de86bb04a3d68be03a37e87622a5ae9cba5861
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Phishing: Spearphishing Attachment T1059.001 Command and Scripting Interpreter: PowerShell

The PDF contains a critical heuristic firing for a malicious redirector link pointing to 'https://ttraff.com/pify?keyword=gilder+lehrman+apush+study+guide'. Additionally, it exhibits characteristics of a PDF SEO link farm, with numerous embedded links to external PDF files, many hosted on Shopify. The ML classifier strongly flagged this PDF as malicious. The primary attack vector appears to be directing users to a malicious URL disguised within the document content.

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.com/pify?keyword=gilder+lehrman+apush+study+guide
    • http://kelatata.atozsmallbusinesservices.com/uploads/1/3/2/6/132680813/462011d6b90dadf.pdf
    • http://files.martismixedmedia.com/uploads/1/3/1/3/131379110/vijukat-wevuxenu-filubodovomobu-fomivizuzetuz.pdf
    • http://nufilita.crestfallentheatre.com/uploads/1/3/1/3/131381241/6595668.pdf
    • https://cdn.shopify.com/s/files/1/0431/0673/0138/files/41781876456.pdf
    • https://cdn.shopify.com/s/files/1/0427/5650/5756/files/adivasi_rodali_dj.pdf
    • https://cdn.shopify.com/s/files/1/0435/3576/1576/files/wuxurizumomijawo.pdf
    • https://cdn.shopify.com/s/files/1/0440/6686/5302/files/23086161695.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/56655156305.pdf
    • https://cdn.shopify.com/s/files/1/0431/1046/5698/files/fovarijezitatigowapi.pdf
    • https://cdn.shopify.com/s/files/1/0434/9735/7472/files/5932472627.pdf
    • https://cdn.shopify.com/s/files/1/0438/4296/1570/files/history_of_badminton_rules_and_regulations.pdf
    • https://cdn.shopify.com/s/files/1/0434/6046/0701/files/91855900530.pdf
    • https://cdn.shopify.com/s/files/1/0435/5905/9615/files/karnataka_election_results_2020.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_off00005fa6.bin
baf521e51eef712ab667db6fa2f3760e5b0682e7f2a84874c742e3441dab4f3c
pdf-font-stream PDF embedded font (sfnt) at offset 0x5FA6 5508 bytes
font_01_sfnt_off0000723d.bin
3f6e719c9cacf2a6e5a6478af5e3b98c42e66e92b0667254edc873c02d4422fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x723D 9956 bytes