Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c751f8e131a5872…

MALICIOUS

PDF

46.3 KB Created: 2020-08-06 22:10:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1b4746f13d31f25c74f5ab89981127f2 SHA-1: f0153bea81e9676c8e7303c2cff2b11f03dcb98c SHA-256: 4c751f8e131a58728e8ce2fb4674dcfb09bb63d9e171f1a87b8bde1c54a0b094
152 Risk Score

Malware Insights

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

The PDF file contains a significant number of embedded links, identified as a PDF link farm. One of the primary links points to a known malicious redirector, ttraff.ru. The ML classifier strongly indicates maliciousness. The document body contains obfuscated text and a URL that appears to be part of the link farm. The primary attack pattern is likely to be SEO manipulation or redirection to malicious 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.ru/pify?keyword=anatomia+y+fisiologia+pancreas+pdf
    • http://files.robindbruce.com/uploads/1/3/2/8/132815002/3148951.pdf
    • http://files.orchid-avenue.net/uploads/1/3/0/7/130776049/23acaa.pdf
    • http://files.tutor.ifljumpstart.com/uploads/1/3/0/7/130775102/d29d501d.pdf
    • http://files.valleypetservices.net/uploads/1/3/2/7/132712324/jowigobulatezuberizi.pdf
    • http://files.pain.euroconferences.org/uploads/1/3/1/0/131070754/5863675.pdf
    • https://cdn.shopify.com/s/files/1/0435/3343/5029/files/40860708880.pdf
    • https://cdn.shopify.com/s/files/1/0428/7679/7081/files/dedem.pdf
    • https://cdn.shopify.com/s/files/1/0431/5804/4823/files/order_of_the_stick.pdf
    • https://cdn.shopify.com/s/files/1/0430/6763/7917/files/72362805269.pdf
    • https://cdn.shopify.com/s/files/1/0437/7473/8586/files/15089928045.pdf
    • https://cdn.shopify.com/s/files/1/0428/7945/1295/files/49622577688.pdf
    • https://cdn.shopify.com/s/files/1/0433/9322/0758/files/rokuk.pdf
    • https://cdn.shopify.com/s/files/1/0430/7353/6149/files/bokeretakedosuzirenaj.pdf
    • https://cdn.shopify.com/s/files/1/0430/2998/7489/files/56010966947.pdf
    • https://cdn.shopify.com/s/files/1/0432/9455/6324/files/pt_cruiser_repair_manual.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_off00007500.bin
226a33f5fe8a4a4ed3e869df9f2e1ecf41d49d559add24e1ab0b625c8f1ad4a8
pdf-font-stream PDF embedded font (sfnt) at offset 0x7500 5564 bytes
font_01_sfnt_off000087e7.bin
d7931ffe3dacfabcf08c55a799cf98bf647cf0b482275d965346a07501c1a77d
pdf-font-stream PDF embedded font (sfnt) at offset 0x87E7 10672 bytes