Malicious PDF — malware analysis report

Static analysis result for SHA-256 856f7678f6699ac8…

MALICIOUS

PDF

41.3 KB Created: 2020-09-01 13:26:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 72afd2d4be4888bb1fd1c4e07e4da369 SHA-1: b8581a422eea2e70d4c7a12c41f8f5961cbe720b SHA-256: 856f7678f6699ac8eac26197f588e2206f0558422daa55d0b512e383e99ab8e6
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded links that redirect to known malicious infrastructure, specifically a URL designed to look like a movie search result. The ML classifier strongly indicated maliciousness, and the PDF_SEO_LINK_FARM heuristic shows a large number of external links, suggesting a link farm or redirection scheme. The document body, though heavily obfuscated, contains the malicious URL and other benign-looking PDF filenames, likely to appear legitimate.

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.com/wix?keyword=basic+instinct+2+full+movie
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/5b9a87_e5fadd7b815c4ea8a315bd48b7711f12.pdf
    • https://static.usrfiles.com/ugd/136d07_06727330b82a43beb2358ecc20c19f22.pdf
    • https://static.usrfiles.com/ugd/b910ae_cc8ea565abfd40a59e9171eb82531286.pdf
    • https://static.usrfiles.com/ugd/f0f215_7c486b05e52749b08f1cb822b22588a7.pdf
    • https://cdn.shopify.com/s/files/1/0435/6780/8667/files/futafobativariwav.pdf
    • https://cdn.shopify.com/s/files/1/0446/0858/5891/files/cambridge_ielts_9.pdf
    • https://cdn.shopify.com/s/files/1/0431/4365/9677/files/7051569821.pdf
    • https://cdn.shopify.com/s/files/1/0437/9777/4497/files/istick_pico_user_manual.pdf
    • https://cdn.shopify.com/s/files/1/0428/5969/2191/files/911_carrera_performance.pdf
    • https://cdn.shopify.com/s/files/1/0432/3688/4642/files/mukuxezolumixigurevanog.pdf
    • https://cdn.shopify.com/s/files/1/0428/7902/5318/files/dukufike.pdf
    • https://cdn.shopify.com/s/files/1/0430/6114/9850/files/kia_cerato_2013_user_manual.pdf
    • https://cdn.shopify.com/s/files/1/0432/9596/5352/files/9384825111.pdf
    • https://cdn.shopify.com/s/files/1/0441/3105/7816/files/geography_hemispheres_worksheet.pdf
    • https://cdn.shopify.com/s/files/1/0437/1791/8875/files/assessing_student_learning_outcomes.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_off00006321.bin
95945b2e99f45d600ea1d8cc986c1650c9e512031df2ceff4ba2f678126ff040
pdf-font-stream PDF embedded font (sfnt) at offset 0x6321 5172 bytes
font_01_sfnt_off000074ba.bin
1d8c22a7765574e21245917c0761b65d3f7b687782d61770437666709e683e3d
pdf-font-stream PDF embedded font (sfnt) at offset 0x74BA 10536 bytes