Malicious PDF — malware analysis report

Static analysis result for SHA-256 121d7ac3a94b8c9a…

MALICIOUS

PDF

95.4 KB Created: 2021-04-03 17:53:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 99671fe729301704cf8295b2dc328dd1 SHA-1: d502fdd7fabef06997478089c19f07ed48b38953 SHA-256: 121d7ac3a94b8c9a57bfdd07e5e50e9e8c02a110fd659b38e4c55ac9d4f963b1
126 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable domains, suggesting a link farm or SEO spam operation. The embedded URL 'https://pelibifir.ru/award?keyword=active+teaching+methods+pdf' indicates a lure to a website that likely hosts malicious content or further phishing attempts. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

Heuristics 5

  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://pelibifir.ru/award?keyword=active+teaching+methods+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4419626/normal_603513dd32568.pdfIn PDF document text
    • http://strongcreditscore.info/how_to_lock_whirlpool_accubake_oven_doorgmxza.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478932/normal_604204b607ead.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460950/normal_601edd020fb6b.pdfIn PDF document text
    • http://wersita.space/133276736865gx19.pdfIn PDF document text
    • http://lady-bug.club/salary_marketing_director_london3v5jk.pdfIn PDF document text
    • http://latuha.com/mififegareniv0z2.pdfIn PDF document text
    • http://interbankdigital.com/schwinn_sidewinder_e_bike_reviewwnj9x.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474176/normal_601f530c1a327.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369774/normal_5fe76e4c614dc.pdfIn PDF document text
    • http://raifaisentapp.online/two_examples_of_cloud_computing_servicesyo86q.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458145/normal_6054f90fe166e.pdfIn PDF document text
    • http://odemebayisitrafik.com/flysky_fs-i6_receiver_binding2k7ya.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489853/normal_605026fe1c0fd.pdfIn PDF document text
    • http://cashthe.ru/what_is_a_summary_of_the_book_the_little_princeczeb2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453579/normal_5fd7b273926bf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366339/normal_602a2ac6d6301.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368740/normal_60031b6c5c4c5.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/bubisifapagefe/android-_x86_installer_is_not_available.pdfIn PDF document text
    • https://s3.amazonaws.com/sorapobuk/fumomedawevitubuj.pdfIn PDF document text
    • https://7e005a1c-fb68-43c1-af83-b854b6a2d282.filesusr.com/ugd/dcfb95_6214190ec50948769fb2489f237d5bd1.pdf?index=trueIn PDF document text
    • https://ddd59a73-be73-4575-bd7b-2e5900175f8b.filesusr.com/ugd/5dc0ef_2596457a1a6b49f393e3e44ba570fc58.pdf?index=trueIn PDF document text
    • https://0778d94d-b67d-49c3-8f6f-43f52d6edec9.filesusr.com/ugd/b85eb0_3f9843fb596446cd8c9fe4154c12757b.pdf?index=trueIn PDF document text
    • https://979cd01f-16ea-4d2c-b189-234964c95597.filesusr.com/ugd/d4c4cf_e3c0066156f04847aabfa9341c227d9d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lakadutof/i_don_quixote_sheet_music_free.pdfIn PDF document text
    • https://9b08d158-0e0f-4203-9b31-e1272d977b1c.filesusr.com/ugd/086daf_fcbf6269adf94d3283e2b81f5fab4e87.pdf?index=trueIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000135b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135B7 5492 bytes
SHA-256: 9ec2f850ce80ceffa0ded61df97eef2ff19075b5640d8fa6a326446e8b871294
font_01_sfnt_off00014852.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14852 11688 bytes
SHA-256: c825b3d7d41a68de97e42d6b2b0fecc4b912cca5c241aff6fc1eed058066969d