Malicious PDF — malware analysis report

Static analysis result for SHA-256 42076a79b4d4cda5…

MALICIOUS

PDF

46.1 KB Created: 2020-09-01 03:42:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2f0b0f8607fe92d0b75866624a9e11f7 SHA-1: 8b1a09120eafee9117ca101bde98c8e2a6bf973f SHA-256: 42076a79b4d4cda5e87247bba46a21a48927f2a9da54a56b3b8524318008f428
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded links, with a critical heuristic firing for PDF_SEO_LINK_FARM indicating a link farm. One of these links, https://ttraff.ru/wix?keyword=adverbios+de+frecuencia+en+frances+pdf, is flagged as a malicious redirector. The ML classifier also strongly indicated maliciousness. The document body contains garbled text and embedded URLs, further supporting the malicious intent.

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/wix?keyword=adverbios+de+frecuencia+en+frances+pdf
    • https://cdn.shopify.com/s/files/1/0440/2990/2998/files/wegewitox.pdf
    • https://cdn.shopify.com/s/files/1/0434/0888/3870/files/povutaweza.pdf
    • https://cdn.shopify.com/s/files/1/0433/0808/9509/files/articulos_cientificos_cortos_para_nios.pdf
    • https://cdn.shopify.com/s/files/1/0434/8670/7876/files/49579778610.pdf
    • https://cdn.shopify.com/s/files/1/0429/0327/3628/files/management_of_beneficial_insects_agrimoon.pdf
    • https://static.usrfiles.com/ugd/0d9a50_6b9db6d3e87a49d2b01b82c7e04f8fbc.pdf
    • https://static.usrfiles.com/ugd/cc089a_a2d6f70782c24cbdb48e4b09c6f675fd.pdf
    • https://cdn.shopify.com/s/files/1/0434/8447/9641/files/potential_evapotranspiration.pdf
    • https://cdn.shopify.com/s/files/1/0435/5306/3063/files/git_add_permission_denied.pdf
    • https://cdn.shopify.com/s/files/1/0431/4493/7623/files/business_intelligence_que_es.pdf
    • https://cdn.shopify.com/s/files/1/0437/8869/7761/files/brand_identity_example.pdf
    • https://cdn.shopify.com/s/files/1/0433/4200/4375/files/rabivawi.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005ee8.bin
65181e962dc27f91cb209139f413578adc078eae0f1539f8bfa940a8f4476be2
pdf-font-stream PDF embedded font (sfnt) at offset 0x5EE8 5108 bytes
font_01_sfnt_off00007048.bin
e09a1875e5699f012b04ededc0becec77cb9b4b6331c62c862c763a91d32d28b
pdf-font-stream PDF embedded font (sfnt) at offset 0x7048 14824 bytes
font_02_sfnt_off00009d4e.bin
cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34
pdf-font-stream PDF embedded font (sfnt) at offset 0x9D4E 4324 bytes