Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5d2abe86c631d8a…

MALICIOUS

PDF

38.8 KB Created: 2020-08-31 05:03:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 07a35a748136a403ce4aaf1f53fbe29f SHA-1: 11e3f4998b30d8bd61a2244406d18a6658a3aad9 SHA-256: f5d2abe86c631d8a091a2978c4f63b491c4ca5503152e91716a741b48d34f5bd
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one specifically pointing to a known malicious redirector. The document body, though heavily obfuscated, contains text related to 'touch math subtraction worksheets printable' and the malicious URL, suggesting a lure for users seeking educational materials. The ML classifier strongly flagged this PDF as malicious, and the presence of a link farm further supports a malicious intent to redirect users.

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=touch+math+subtraction+worksheets+printable
    • https://static.usrfiles.com/ugd/a76634_cd8671245a6846869458c161b68f950f.pdf
    • https://static.usrfiles.com/ugd/e4ff69_c81dda769c844d5083037bd0b796e8f1.pdf
    • https://static.usrfiles.com/ugd/fb83f1_c9e0daa246b347d9a6fe4ab650700127.pdf
    • https://cdn.shopify.com/s/files/1/0457/3695/1964/files/68672943488.pdf
    • https://static.usrfiles.com/ugd/8dde66_db8c508ef5cc46d8b9c60dfa48d63e57.pdf
    • https://static.usrfiles.com/ugd/b8c837_4b9746658cfc488088f5c7229684231e.pdf
    • https://static.usrfiles.com/ugd/b8c837_d6be4d119454488385e544be8e0be150.pdf
    • https://static.usrfiles.com/ugd/9c43ec_2ffd6ffdef59420da3030e42fe90a4da.pdf
    • https://cdn.shopify.com/s/files/1/0438/1189/7504/files/fabiwufolurewabe.pdf
    • https://cdn.shopify.com/s/files/1/0438/4840/1046/files/letidafifitusiwonevegun.pdf
    • https://cdn.shopify.com/s/files/1/0438/2746/2301/files/kensei_combo_guide.pdf
    • https://cdn.shopify.com/s/files/1/0439/7613/0718/files/apple_cider_vinegar_diet_plan.pdf
    • https://cdn.shopify.com/s/files/1/0431/7777/1164/files/nigukupisesudanumiforot.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_off000059ad.bin
c42ab319aaf1aa9292a89a9192e33e22060d80ec9bdb0c21fa38f21b0ea3a02a
pdf-font-stream PDF embedded font (sfnt) at offset 0x59AD 5416 bytes
font_01_sfnt_off00006c00.bin
9b315147c7c7f0eb5ae38fa6e0ec22ec095f490fb004b0ad3b6f84f16d732dee
pdf-font-stream PDF embedded font (sfnt) at offset 0x6C00 9940 bytes