Malicious PDF — malware analysis report

Static analysis result for SHA-256 41cbf8becbbc1e87…

MALICIOUS

PDF

39.4 KB Created: 2020-08-15 08:25:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1307a7396713ae22b5a82486e5eccb34 SHA-1: c1a8c02196863291fa60e85d2af72b4373d17e73 SHA-256: 41cbf8becbbc1e87664a403644ff066ba3f5669d2e7b6acc109efa394ed40252
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with a critical heuristic identifying a link to known malicious redirector infrastructure. The document body, though obfuscated, contains a URL pointing to the same malicious redirector. This suggests the primary intent is to lure the user into clicking the link, leading to a malicious site. The ML classifier strongly supports the malicious nature of this PDF.

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/wb?keyword=endothermic%20and%20exothermic%20reaction%20notes%20worksheet
    • http://bejedifi.toolstorm.ca/uploads/1/3/0/7/130739297/8979404.pdf
    • http://vuzuv.jamaicanamericanbar.com/uploads/1/3/1/4/131408024/3062673.pdf
    • http://files.body-knowledge.com/uploads/1/3/2/6/132681824/2094315.pdf
    • http://files.cavallindesign.com/uploads/1/3/1/4/131407102/4e021d.pdf
    • https://cdn.shopify.com/s/files/1/0435/8999/2605/files/how_to_check_cudnn_version.pdf
    • https://cdn.shopify.com/s/files/1/0430/5630/0186/files/12323315624.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/kosetomamevisired.pdf
    • https://cdn.shopify.com/s/files/1/0432/0903/1840/files/wifokazunuzazuna.pdf
    • https://cdn.shopify.com/s/files/1/0435/6974/1983/files/54693679040.pdf
    • https://cdn.shopify.com/s/files/1/0448/0742/2109/files/9th_grade_biology_book_online.pdf
    • https://cdn.shopify.com/s/files/1/0434/4345/4102/files/manual_boss_me_80_portugues.pdf
    • https://cdn.shopify.com/s/files/1/0432/5313/7576/files/vibarixewigupi.pdf
    • https://cdn.shopify.com/s/files/1/0429/4053/0854/files/malekemuturepugawanu.pdf
    • https://cdn.shopify.com/s/files/1/0438/0252/5856/files/xiranojafoxor.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_off00005959.bin
959f99783356be34857f16b9a6cd5fa3bb07acf12dfc7fc8ca32142ac2134716
pdf-font-stream PDF embedded font (sfnt) at offset 0x5959 5328 bytes
font_01_sfnt_off00006b59.bin
ecac55fc5d7b57b03a000efe5c2ba51d84680ffc4118001e8ff9e301771011a0
pdf-font-stream PDF embedded font (sfnt) at offset 0x6B59 10920 bytes