Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb6d1fc6d67c5f3e…

MALICIOUS

PDF

41.8 KB Created: 2020-08-30 02:45:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c577bdca5b002944d713d85922fc9322 SHA-1: c62fdff2084ac227d65912afa38d427217a71284 SHA-256: cb6d1fc6d67c5f3efa066279499bff3507736ff7de9fbaa76d190e5962c65e48
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to 'ttraff.ru'. This link is embedded within the document body, which also contains a keyword related to 'dont starve together pets' to entice clicks. The PDF also exhibits characteristics of a link farm, with numerous embedded URLs, many hosted on Shopify. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious redirector lure.

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=dont+starve+together+pets
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kovutuku.pdf
    • https://cdn.shopify.com/s/files/1/0432/1103/0683/files/21126208627.pdf
    • https://cdn.shopify.com/s/files/1/0428/2135/3635/files/41131511300.pdf
    • https://cdn.shopify.com/s/files/1/0432/7663/2217/files/b_pharmacy_online_form_last_date_2018.pdf
    • https://static.usrfiles.com/ugd/b8c837_eb335737a47b4a68aba77d7ba136fa2a.pdf
    • https://static.usrfiles.com/ugd/0286dd_7603e3a07dc54c0a9ad483257f80fe8c.pdf
    • https://cdn.shopify.com/s/files/1/0434/1576/5153/files/the_reasonableness_of_christianity_john_locke.pdf
    • https://cdn.shopify.com/s/files/1/0437/6923/3565/files/circumference_and_area_worksheets_for_7th_grade.pdf
    • https://cdn.shopify.com/s/files/1/0434/7707/4077/files/fahrenheit_451_part_1_summary.pdf
    • https://cdn.shopify.com/s/files/1/0432/9262/3013/files/cuaderno_de_las_vocales_para_imprimir.pdf
    • https://cdn.shopify.com/s/files/1/0440/0657/2197/files/angrist_mastering_metrics.pdf
    • https://cdn.shopify.com/s/files/1/0437/7447/6440/files/48217066137.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_off000065d7.bin
beb32bec6c9cc9326b0ab50411cf60bfaf9e35eb6b704e1175f6cfbd5b4fda4c
pdf-font-stream PDF embedded font (sfnt) at offset 0x65D7 5108 bytes
font_01_sfnt_off0000773d.bin
e66d00044f8d1e0dece508ff4e5093a6c7112f98f79242f6ea131448465b5b59
pdf-font-stream PDF embedded font (sfnt) at offset 0x773D 10388 bytes