Malicious PDF — malware analysis report

Static analysis result for SHA-256 86f838ee9d757de1…

MALICIOUS

PDF

40.1 KB Created: 2020-08-30 00:12:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c1721d7bc581f7397a7f6e2b9470f7e8 SHA-1: dbf333e055cc3d952db0c20f16efa07663d7be52 SHA-256: 86f838ee9d757de14763c8b64b17610f255021c651b898cad0b93d8c20a3532a
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded links, one of which points to a known malicious redirector. The document body, though heavily obfuscated, also contains a URL that appears to be a lure for practice materials. The presence of numerous external PDF links, many pointing to benign Shopify URLs, suggests a link farm or SEO poisoning tactic to increase visibility of the malicious redirector.

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.cc/wix?keyword=emsat+arabic+practice+with+answers
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0432/1008/0420/files/bo3_zombies_shadows_of_evil_guide.pdf
    • https://cdn.shopify.com/s/files/1/0431/8072/0294/files/gonokugamizela.pdf
    • https://cdn.shopify.com/s/files/1/0431/7678/8117/files/film_anarchist_from_colony_sub_indo.pdf
    • https://cdn.shopify.com/s/files/1/0431/0754/9338/files/rectangular_prism_worksheet.pdf
    • https://static.usrfiles.com/ugd/b8c837_904df9d6f3e7497d9e046fb0e9cc5efe.pdf
    • https://static.usrfiles.com/ugd/b11f6d_92b1c03c326d4ce2a3c6e5ab4213ea42.pdf
    • https://cdn.shopify.com/s/files/1/0431/5663/5804/files/wow_argus_reach_rep_guide.pdf
    • https://cdn.shopify.com/s/files/1/0434/5797/0329/files/castle_learning_answers_physics.pdf
    • https://cdn.shopify.com/s/files/1/0437/0432/0154/files/what_is_hello_in_pig_latin.pdf
    • https://static.usrfiles.com/ugd/b8c837_11efaf39fdf346398699d2fd99adfbc7.pdf
    • https://static.usrfiles.com/ugd/ade4e6_fdff9db4f89a479a98a2e4020480c0b7.pdf
    • https://static.usrfiles.com/ugd/b0b521_0a366a2599cd4115b62a6ba80886226a.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_off00005ea4.bin
b7f9c26427a70f7d14ba9b82d36b79b482058769e59dea96c950d0477a3c89ab
pdf-font-stream PDF embedded font (sfnt) at offset 0x5EA4 5328 bytes
font_01_sfnt_off000070ae.bin
a9a2b2ec928b57b86a49d4d1f51fd97f741e62fb66fd7f626a774853f5fc769d
pdf-font-stream PDF embedded font (sfnt) at offset 0x70AE 10408 bytes