Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5d5f37f06bd79dc…

MALICIOUS

PDF

48.7 KB Created: 2020-09-07 16:59:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c8be5af370620923b332fc1329ea7428 SHA-1: 828374c55a4628c8a834738ac4ec7c0065a5e95c SHA-256: c5d5f37f06bd79dce3c47154a3d3e477e136844d6647e51d5a7b108be1dcad4f
152 Risk Score

Malware Insights

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

The PDF contains a link to a known malicious redirector infrastructure, disguised with text related to tax form instructions. The ML classifier strongly indicated maliciousness. The document body, though heavily obfuscated, contains the URL and references to 'amended form 1040 instructions', reinforcing the lure. The presence of a large number of external PDF links suggests a link farm designed to distribute malicious content or improve SEO for malicious sites.

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.club/wix?keyword=amended+form+1040+instructions
    • https://static.usrfiles.com/ugd/d4a9d6_7167939ee3294a03bbe4703fdcf48c72.pdf
    • https://static.usrfiles.com/ugd/c1de29_bcc5e2279c0b4560be4949b4740c77fd.pdf
    • https://static.usrfiles.com/ugd/f3ecbe_97bd36b5fe9e46f4afdbe539a368d7b0.pdf
    • https://static.usrfiles.com/ugd/19103d_f7a31c7996f7422aa132e9e8f7f645f7.pdf
    • https://static.usrfiles.com/ugd/77d535_67893d849c434b63a6b2b0bc422a383a.pdf
    • https://static.usrfiles.com/ugd/d43733_9b8d1a8cecb04d63955c930ffe8857e7.pdf
    • https://static.usrfiles.com/ugd/451461_747bef847fbd4be18b7391a89c882d6a.pdf
    • https://static.usrfiles.com/ugd/79e0dc_b62de3f9d5724723a0729578ea469c58.pdf
    • https://static.usrfiles.com/ugd/f99735_92af2592241c4f9ba456f0758313ead1.pdf
    • https://static.usrfiles.com/ugd/ee9d3f_18291800a2074e198cb818607aa7e41d.pdf
    • https://cdn.shopify.com/s/files/1/0437/9086/0437/files/barbara_cartland_books_free_download.pdf
    • https://cdn.shopify.com/s/files/1/0434/8998/4674/files/coffee_blending_guide.pdf
    • https://static.usrfiles.com/ugd/409ca8_fc5a4d8f2d7240ee9fd4b80f19f61694.pdf
    • https://static.usrfiles.com/ugd/b8c837_ca151381f9394268b8693c1c0c148694.pdf
    • https://static.usrfiles.com/ugd/5bb01c_f4fd3dce36df4d77ba54cad5d5b0fe5f.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_off00008063.bin
3557d77526e499b876eee21c19db87ffa0c2c2af3aaef743e80ac0368312c3bb
pdf-font-stream PDF embedded font (sfnt) at offset 0x8063 5196 bytes
font_01_sfnt_off0000920a.bin
e8840b6e0990e9f9fe684862c9d790e2465bb19450444057f47ba29016c7909b
pdf-font-stream PDF embedded font (sfnt) at offset 0x920A 10544 bytes