Malicious PDF — malware analysis report

Static analysis result for SHA-256 537955d3e497d1f6…

MALICIOUS

PDF

75.2 KB Created: 2021-04-19 04:50:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 5d5d91c73de9a7d6f1e77fb063e9a13f SHA-1: 27567a3af12c9b27ece7369bd957714b662cb2bb SHA-256: 537955d3e497d1f6810927b0186a43770a685be4f5ed7259d36e25b8823a96d3
96 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a significant number pointing to potentially malicious domains, indicating a link farm or distribution mechanism. The embedded content, though heavily obfuscated, suggests an attempt to disguise the malicious intent. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://kuzutuzo.ru/strik?utm_term=two+major+rivers+in+the+us
    • https://nujetamewude.weebly.com/uploads/1/3/4/8/134881912/9852253.pdf
    • https://litusavetedi.weebly.com/uploads/1/3/4/4/134445261/eae7def7df1.pdf
    • https://cdn.sqhk.co/murajefovel/ghhhvha/run_tv_cast_2020.pdf
    • http://boziliruzake.22web.org/viability_of_the_business.pdf
    • https://zarixurumis.weebly.com/uploads/1/3/1/4/131406049/buxuzujevuziseb_gunojuxegasu.pdf
    • https://cdn.sqhk.co/josipinu/iigcgjf/how_can_fear_be_used_to_manipulate_essay.pdf
    • https://cdn.sqhk.co/numiwuzuwix/zEriggd/41158149461.pdf
    • https://jotogenawe.weebly.com/uploads/1/3/1/4/131406354/tezukitusetaj_mepuveburorefu_dexuvoxam.pdf
    • https://cdn.sqhk.co/doxinotilid/dmib75b/47938577414.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://878ee1be-828d-48b9-a24a-84283cf66a1c.filesusr.com/ugd/86936c_d2a154143e294b6980ea0906b18a8170.pdf?index=true
    • https://s3.amazonaws.com/tarajix/gabiboregumeloxoxufason.pdf
    • https://s3.amazonaws.com/lomuper/berkshire_polar_fleece_sheets_queen.pdf
    • https://0c6b7a74-1ca0-41da-943c-c268a208a416.filesusr.com/ugd/fef373_60b77552af58485c910719168dededcd.pdf?index=true
    • http://gogibesu.rf.gd/7500585182.pdf
    • https://s3.amazonaws.com/zuses/nalonizosezinu.pdf
    • http://luwulifinuneti.epizy.com/tcu_guide_book_2019_20.pdf
    • https://s3.amazonaws.com/dinisemowoge/48332386825.pdf
    • https://s3.amazonaws.com/penale/functions_of_the_heart_worksheet.pdf
    • https://584abdf6-e408-48d3-a53c-4313a8f82471.filesusr.com/ugd/18ee90_62fa956b493c44c88bdab3e0eec82685.pdf?index=true
    • 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_off0000e8aa.bin
4a03d67790a646a4befba4e2272da6fe2eb04fb46c8cf5c2e9869099421fe4e7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8AA 5072 bytes
font_01_sfnt_off0000f9d0.bin
be68c965a3f39bc17f213661667292513a0441514e726a13dea97d18b170d1a1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D0 11088 bytes