Malicious PDF — malware analysis report

Static analysis result for SHA-256 0fb4968ed9745269…

MALICIOUS

PDF

54.1 KB Created: 2020-09-03 01:43:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 60deb7a5f73e835f1e5c616d322b1a1a SHA-1: 561daeb66ec51cb4471c4ae56ab3d995705d96bf SHA-256: 0fb4968ed9745269a521a8d4b9383f312fe2eac87ab5eecd8a3027bb491b2fde
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, many of which point to a redirector service. The document body, though heavily obfuscated, contains text suggesting it is a lure for 'pre algebra math worksheets pdf'. The primary malicious IOC is the redirector URL, which is likely used to funnel victims to further malicious content. The ML classifier strongly indicates maliciousness.

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.link/wix?keyword=pre+algebra+math+worksheets+pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/934fc3_6b1340f202a84ad5aa638b6edc2f7663.pdf
    • https://static.usrfiles.com/ugd/1c8c6c_f3693cca9b644ca0ae6a566012795535.pdf
    • https://static.usrfiles.com/ugd/1f5cef_d63f6fe9f26b45b8b476838d2b81e367.pdf
    • https://cdn.shopify.com/s/files/1/0438/0069/0848/files/aphthous_stomatitis.pdf
    • https://cdn.shopify.com/s/files/1/0446/1376/3235/files/ich_guidelines_for_method_validation.pdf
    • https://cdn.shopify.com/s/files/1/0431/3038/8642/files/71546421196.pdf
    • https://cdn.shopify.com/s/files/1/0431/5978/1538/files/vijubezitisuk.pdf
    • https://cdn.shopify.com/s/files/1/0435/5129/3603/files/bankofamerica._com_mynewcard.pdf
    • https://cdn.shopify.com/s/files/1/0428/6640/9639/files/tinukam.pdf
    • https://cdn.shopify.com/s/files/1/0429/6730/2303/files/dell_poweredge_r740xd_specs.pdf
    • https://cdn.shopify.com/s/files/1/0434/2746/3324/files/89421616249.pdf
    • https://cdn.shopify.com/s/files/1/0431/7990/1085/files/welek.pdf
    • https://static.usrfiles.com/ugd/d4579c_87c3f3596baf48f395603a4eac347a69.pdf
    • https://static.usrfiles.com/ugd/b8c837_0887dcaaabfa42f485b4679c9130eee4.pdf
    • https://static.usrfiles.com/ugd/b8c837_3b60954656eb4c149fba766bfe93ab8f.pdf
    • https://static.usrfiles.com/ugd/f3ecbe_dd74ffe29c7942ec84cc00ef7d36d1a7.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_off00009418.bin
fe6a7034fe8edb2bbedb78bd43941ecb7b6785d1369d0f83a2b9b21eac2c6637
pdf-font-stream PDF embedded font (sfnt) at offset 0x9418 5752 bytes
font_01_sfnt_off0000a792.bin
f4427b767c4ee6e6e723a2667dd893889cc89084d37d6fb18255cdc57cd6b403
pdf-font-stream PDF embedded font (sfnt) at offset 0xA792 10480 bytes