Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c8eb0281cbdd25a…

MALICIOUS

PDF

44.1 KB Created: 2020-08-20 03:29:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0b4db391ce07c749f3fbbf32499b953c SHA-1: ad8ca984d73c02d841156c70815be12234abf5a2 SHA-256: 4c8eb0281cbdd25ad393e8eac16c096260f36055c14b183763df56d0d52e84b3
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating it links to known malicious redirector infrastructure. The document body, though partially corrupted, contains text related to 'context clues worksheets printable' and includes the primary malicious URL. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is designed to redirect users to harmful 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.ru/pify?keyword=context+clues+worksheets+printable
    • http://mijuki.junc2funkt.com/uploads/1/3/1/4/131412032/vuzowuv.pdf
    • http://zatusow.flaniganssportsworld.com/uploads/1/3/2/6/132682883/e01a20f959e5b13.pdf
    • https://cdn.shopify.com/s/files/1/0440/2610/1910/files/jajiri.pdf
    • https://cdn.shopify.com/s/files/1/0435/4496/9367/files/55486573619.pdf
    • https://cdn.shopify.com/s/files/1/0430/7720/6167/files/dna_amplification_by_pcr.pdf
    • https://cdn.shopify.com/s/files/1/0445/5759/8884/files/ccsp_official_study_guide.pdf
    • https://cdn.shopify.com/s/files/1/0447/3418/5628/files/cricket_score_sheet_for_6_overs_download.pdf
    • https://cdn.shopify.com/s/files/1/0434/9391/6837/files/zexikakip.pdf
    • https://cdn.shopify.com/s/files/1/0433/0350/1989/files/rarinubejonupusivupuk.pdf
    • https://cdn.shopify.com/s/files/1/0437/0602/4090/files/blank_july_2019_calendar_printable.pdf
    • https://cdn.shopify.com/s/files/1/0430/8788/8551/files/720p_hd_camera_eyewear_user_manual.pdf
    • https://cdn.shopify.com/s/files/1/0431/2452/3169/files/33029891205.pdf
    • https://cdn.shopify.com/s/files/1/0432/5651/2667/files/75066402896.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_off0000691a.bin
0b3f585cea00a62bd28c7dec1c9c948b61e04e2a18472bcaaf525a15d5698dee
pdf-font-stream PDF embedded font (sfnt) at offset 0x691A 5292 bytes
font_01_sfnt_off00007b20.bin
ddfa8f5e7bd22e6937a97cd230044cfb60e403bb1e1cca8dfab07adc7a2e899a
pdf-font-stream PDF embedded font (sfnt) at offset 0x7B20 12096 bytes