Malicious PDF — malware analysis report

Static analysis result for SHA-256 61b51041a8af1f05…

MALICIOUS

PDF

73.3 KB Created: 2021-06-14 10:58:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: f891ef07dd2be59dc2e8c94d6b34dcd1 SHA-1: ca18b5f71ccc7fa0d336a4f35cfac2008df91a52 SHA-256: 61b51041a8af1f054eba1c6937f607f028fd1b498b795c09831e18f7e54c6e30
186 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, many pointing to disposable domains, which is characteristic of link farms used for SEO manipulation or to host phishing content. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were extracted, the presence of numerous external URLs suggests an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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 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://krisoc.ru/pbw?utm_term=route+9+pokemon+brick+bronze PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4416802/normal_600c4a00a3145.pdfIn PDF document text
    • https://sinijeba.weebly.com/uploads/1/3/5/3/135329812/petukagudofom.pdfIn PDF document text
    • https://bavimukirisami.weebly.com/uploads/1/3/1/4/131482950/5e5a6e35fcd6.pdfIn PDF document text
    • https://risimapi.weebly.com/uploads/1/3/4/3/134321435/bakejiwozaxufulew.pdfIn PDF document text
    • https://kekomefokusun.weebly.com/uploads/1/3/7/5/137511549/7545432.pdfIn PDF document text
    • https://waleberof.weebly.com/uploads/1/3/4/3/134385841/lavatususokiziwow.pdfIn PDF document text
    • https://renesixedobalew.weebly.com/uploads/1/3/0/9/130969137/didalivijuj-menoji-faxigokinitak.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370068/normal_6016c906f27b0.pdfIn PDF document text
    • https://zitobejamowimuk.weebly.com/uploads/1/3/4/6/134623616/421bc67f5.pdfIn PDF document text
    • https://kibasixeb.weebly.com/uploads/1/3/1/4/131438563/lofivaxikuwakanigos.pdfIn PDF document text
    • https://fazugiwe.weebly.com/uploads/1/3/4/0/134012697/8570350.pdfIn PDF document text
    • https://pasodevoz.weebly.com/uploads/1/3/5/3/135345373/6698f805da.pdfIn PDF document text
    • https://noduxexoretan.weebly.com/uploads/1/3/5/9/135993764/mapuvixe.pdfIn PDF document text
    • https://numokupe.weebly.com/uploads/1/3/4/8/134857704/rupubur.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xutipofapu.pbworks.com/f/68077954268.pdfIn PDF document text
    • http://mamejoniza.pbworks.com/w/file/fetch/144658803/12212815012.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4130c85b-2120-433c-881f-f4ad1db42480/calcul_de_ph_exercices_corrigs.pdfIn PDF document text
    • http://mijatonevu.pbworks.com/w/file/fetch/145259631/direct_and_indirect_speech_worksheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/741c91eb-cb91-48a0-912c-d1b54884be77/que_es_la_comunicacin_corporativa_u_organizacional.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ea9fa942-5214-4f26-8fde-48142d6bc791/tobonidizarupesegajafewu.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_off0000dfa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFA7 5076 bytes
SHA-256: a02a78bf4b003781431f9537c0225b76703a226cc842b1527ce3aec0ce9ec6f1
font_01_sfnt_off0000f0e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E7 11248 bytes
SHA-256: dc3fc913fc865645f9a5c5ba1a2eb76702a7d66d07dd7c25fc8b3a4cc92d9b6e