Malicious PDF — malware analysis report

Static analysis result for SHA-256 21f3a61535e20bc3…

MALICIOUS

PDF

36.2 KB Created: 2020-08-07 07:24:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9973f6ba8d55810f88e4ac52d00b30b9 SHA-1: e3a32ace7c3183621f59f26e1120e7fd65daea78 SHA-256: 21f3a61535e20bc3a67e1750c3bb1c8b7cf6129f4ffc78e9da5faa1b9f700f3e
150 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with one specifically pointing to a known malicious redirector. The heuristic PDF_SEO_LINK_FARM indicates a link farm structure, suggesting the primary purpose is to distribute malicious links. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted, but the extensive link farm and redirector URL are sufficient indicators of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 3

  • 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.
  • 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=barrancos+operatoria+dental+pdf
    • http://files.redmosaicjewelry.com/uploads/1/3/0/7/130776619/kuxabatitupi-rafewudijig.pdf
    • http://busasumuw.chriswalasekaudio.com/uploads/1/3/1/4/131407241/1824444.pdf
    • http://files.steverustmusic.com/uploads/1/3/0/7/130775649/nulikurafape.pdf
    • http://files.singularityfanpages.com/uploads/1/3/1/8/131857631/12d5ade7.pdf
    • http://files.liloli.org/uploads/1/3/0/8/130874360/sotazajas.pdf
    • https://cdn.shopify.com/s/files/1/0433/0281/3849/files/joridorememogadapiboja.pdf
    • https://cdn.shopify.com/s/files/1/0440/7685/9557/files/argentina_debt_restructuring.pdf
    • https://cdn.shopify.com/s/files/1/0428/5513/7447/files/zibikegaxa.pdf
    • https://cdn.shopify.com/s/files/1/0437/1893/4677/files/bioelectricity_a_quantitative_approach_solution_manual.pdf
    • https://cdn.shopify.com/s/files/1/0432/5900/3038/files/9099979453.pdf
    • https://cdn.shopify.com/s/files/1/0429/8512/8090/files/split_files_free_software.pdf
    • https://cdn.shopify.com/s/files/1/0437/0500/8293/files/jamupu.pdf
    • https://cdn.shopify.com/s/files/1/0432/3108/4708/files/41261803217.pdf
    • https://cdn.shopify.com/s/files/1/0433/5989/5717/files/16593370722.pdf
    • https://cdn.shopify.com/s/files/1/0438/3683/3954/files/expresiones_mas_comunes_en_ingles.pdf
    • https://cdn.shopify.com/s/files/1/0432/7027/5237/files/69850503956.pdf
    • https://cdn.shopify.com/s/files/1/0429/8450/5498/files/47942757432.pdf
    • https://cdn.shopify.com/s/files/1/0433/8365/2506/files/85644886679.pdf
    • https://cdn.shopify.com/s/files/1/0431/3877/7249/files/92646365428.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/
    • https://cdn.shopify.com/s/files/1/0431/3877/7249/files/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00004fc1.bin
6faf1e21c015122ead20646acff877e0d9896315e40216cb5a096740730cb56e
pdf-font-stream PDF embedded font (sfnt) at offset 0x4FC1 5200 bytes
font_01_sfnt_off00006180.bin
2a865080421e17f04069a42e1ba661a0ba1994008daf0aa603189443f4601c6f
pdf-font-stream PDF embedded font (sfnt) at offset 0x6180 10020 bytes