Malicious PDF — malware analysis report

Static analysis result for SHA-256 0ef8159c9b5c6152…

MALICIOUS

PDF

36.0 KB Created: 2020-08-08 17:45:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: b0e9f9980b5d95b2a7d53afd8115433d SHA-1: e1e31aa4052d76e228c797c6f01e0d1c60325b44 SHA-256: 0ef8159c9b5c6152825c2cb216374a04f57fc0b2cb27c3ab30ca098c58a63401
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, including one that redirects to malicious infrastructure, disguised as a download for an English grammar book. The ML classifier strongly indicated maliciousness, and the PDF_MALICIOUS_REDIRECTOR_LINK heuristic confirms the presence of a link to a known malicious redirector. The document body itself is heavily obfuscated but contains the primary malicious URL.

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=a+practical+english+grammar+exercises+4th+edition+pdf
    • http://judabiver.indiansinwinnipeg.com/uploads/1/3/2/6/132681352/7617d57d3b74.pdf
    • http://files.theresearchmonster.com/uploads/1/3/0/8/130814588/devolube.pdf
    • http://files.goaskalex.org/uploads/1/3/1/3/131381109/vurega_parumusuleda_kaxaxujatiw_fuzuwudesef.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0428/3308/4575/files/jotabipazu.pdf
    • https://cdn.shopify.com/s/files/1/0429/2214/8003/files/2625297800.pdf
    • https://cdn.shopify.com/s/files/1/0437/6389/2375/files/awards_2020_19.pdf
    • https://cdn.shopify.com/s/files/1/0437/5203/0357/files/lojajekumixif.pdf
    • https://cdn.shopify.com/s/files/1/0434/4040/6684/files/wunadamimiwesavakov.pdf
    • https://cdn.shopify.com/s/files/1/0437/7464/0286/files/14479068499.pdf
    • https://cdn.shopify.com/s/files/1/0449/2853/2635/files/basics_of_economics_for_upsc.pdf
    • https://cdn.shopify.com/s/files/1/0432/6568/7717/files/75515191839.pdf
    • https://cdn.shopify.com/s/files/1/0432/6119/8491/files/20140646695.pdf
    • https://cdn.shopify.com/s/files/1/0430/8018/8058/files/22706946281.pdf
    • https://cdn.shopify.com/s/files/1/0432/6775/2099/files/7733188816.pdf
    • https://cdn.shopify.com/s/files/1/0431/2272/0922/files/carcassonne_board_game_rules.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00004d8a.bin
8c9791a5ea0b2b92344627fc4cc919bc68bbd1a069b5a5c45322ec0de6a913b0
pdf-font-stream PDF embedded font (sfnt) at offset 0x4D8A 5712 bytes
font_01_sfnt_off000060dc.bin
99893643c23df8209a6330bf2e5f71be2e52bd655dab7d5ef655ccf7215de515
pdf-font-stream PDF embedded font (sfnt) at offset 0x60DC 9868 bytes