Malicious PDF — malware analysis report

Static analysis result for SHA-256 656658fa6cf6aaa9…

MALICIOUS

PDF

67.9 KB Created: 2021-03-30 07:50:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 84485f3bbb58551c5ada4972bd4a9331 SHA-1: 7e8146855ce2ac891ad973c325841e10a0e62696 SHA-256: 656658fa6cf6aaa9691618a12c7afeb595c4135c69e234fb7ac0659d0a61b2ed
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs pointing to a link farm hosted on disposable domains, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The primary IOC is the initial URL used to access the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://midufefew.ru/strik?utm_term=copper+pipe+size+chart+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4409796/normal_6057a3d065df5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415530/normal_602e5024a9032.pdfIn PDF document text
    • https://cdn.sqhk.co/reriwoduriju/nEIheif/26423587405.pdfIn PDF document text
    • https://cdn.sqhk.co/ruzixapudel/U2je7ge/kefazevobup.pdfIn PDF document text
    • http://xomerisupudegop.medianewsonline.com/certificate_of_insurance_example.pdfIn PDF document text
    • http://poxumanavofeboz.scienceontheweb.net/celestial_navigation_books_free_download.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454556/normal_5fcb52eaeab1c.pdfIn PDF document text
    • http://zefujixa.mywebcommunity.org/muzidubimubifanin.pdfIn PDF document text
    • http://kiwenalod.medianewsonline.com/kupididukafezopuwibekule.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375503/normal_603f0b2a1f947.pdfIn PDF document text
    • http://lomigakorak.getenjoyment.net/31572848247.pdfIn PDF document text
    • http://vegunax.getenjoyment.net/nibikopuwudarezakat.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6205d428-d5dc-494e-bbc3-e2236f9d811e.filesusr.com/ugd/6885a6_99c317a98c6a4d32866ff5b75ecbca4c.pdf?index=trueIn PDF document text
    • https://7ec9ed57-df89-401a-953b-45744c150cee.filesusr.com/ugd/6e3131_f8cd913c8b69425eb4c1e223777e24ec.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/53fc71be-dfe5-4d04-ae88-90e9d3255f0b/97218822781.pdfIn PDF document text
    • https://9526c93a-d340-4dca-b5fd-2864ff0888c4.filesusr.com/ugd/4c3d6a_34594aa23b9b47c7bba9e0ec53566587.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/5c078a26-9465-42f5-b819-590df2f9b44e/nemanofagebukamiti.pdfIn PDF document text
    • http://vapewokadovusa.myartsonline.com/trigeminal_nerve_anatomy.pdfIn PDF document text
    • https://156bb51f-0b62-477f-88ca-8620af00812b.filesusr.com/ugd/e3ff21_b63910c4c62845238049064fcadf51a9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1acacfb8-bf80-4bdf-ad51-750b3098396d/what_size_is_16_cm_in_inches.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc2c70d3-c9cb-4ecd-90a5-4d248f1cadcc/kodorugojazeb.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/86969d41-6e36-48ec-86a7-29fb60036c31/damekawalaxofewatakufa.pdfIn PDF document text
    • https://21319658-e817-4d6a-846f-872ccfe0f0c2.filesusr.com/ugd/982af2_cd66fbe9ce0045ddb13d5f05ceb4fb52.pdf?index=trueIn PDF document text
    • http://gajutar.onlinewebshop.net/senodizipegepab.pdfIn 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_off0000cd4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD4E 5168 bytes
SHA-256: 14efe35ebca97132bd1ae5e0fb3de5f986f3132a5228a79d6598e3398d927363
font_01_sfnt_off0000dee1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEE1 10392 bytes
SHA-256: b42ba77fdff16503998341fdf571318ab700f9b95c0042f4021d8e46efbbd012