Malicious PDF — malware analysis report

Static analysis result for SHA-256 8834ea609ece5dc4…

MALICIOUS

PDF

68.4 KB Created: 2021-05-09 08:56:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 1723e64e4298c46942e6db052997079e SHA-1: 2191d874813751797f3558518ac6dba5e93e281e SHA-256: 8834ea609ece5dc4623759d4a5c11ee6f01fb05ac281ec3e11a7a9bca610e0b4
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous external URLs pointing to other PDF documents, many hosted on disposable domains, suggesting an attempt to manipulate search engine results or distribute further malicious content. The presence of multiple external links and the overall structure strongly indicate a phishing or SEO spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://zajinet.ru/strik?utm_term=factoring+polynomials+khan+academy PDF link annotation
    • https://demaxezobenila.weebly.com/uploads/1/3/1/8/131856353/5709917b0c6a9.pdfIn PDF document text
    • http://faxixovojaja.sportsontheweb.net/wixerix.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481402/normal_606782d26c3b7.pdfIn PDF document text
    • https://wetogukonitama.weebly.com/uploads/1/3/3/9/133997956/bffe1f92e47.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375896/normal_60208356d0e85.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4461229/normal_60158fc3858c0.pdfIn PDF document text
    • https://bunekapizo.weebly.com/uploads/1/3/0/9/130969144/817201.pdfIn PDF document text
    • https://fanuxerejupu.weebly.com/uploads/1/3/1/3/131398214/1498561.pdfIn PDF document text
    • https://cdn.sqhk.co/pilimisoduk/aibfmib/small_business_retirement_plans_2020.pdfIn PDF document text
    • https://sezorataxij.weebly.com/uploads/1/3/4/6/134600708/rizebidolem.pdfIn PDF document text
    • https://zavegikow.weebly.com/uploads/1/3/4/8/134884987/f017a28.pdfIn PDF document text
    • https://lobavasato.weebly.com/uploads/1/3/1/4/131483685/2896697.pdfIn PDF document text
    • https://munuteme.weebly.com/uploads/1/3/4/8/134862418/6010835.pdfIn PDF document text
    • https://xemageka.weebly.com/uploads/1/3/1/3/131380316/6a1489fde7.pdfIn PDF document text
    • http://penageli.getenjoyment.net/additive_manufacturing_technologies_gibson_download.pdfIn PDF document text
    • https://doxefifuz.weebly.com/uploads/1/3/0/9/130969363/walotume-mapewamabex.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417045/normal_6056aafb72bc7.pdfIn PDF document text
    • http://pokinusuvato.getenjoyment.net/revista_caamo_colombia.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385636/normal_5fd93e81118ea.pdfIn PDF document text
    • http://budivev.scienceontheweb.net/parliamentary_system_of_uk.pdfIn PDF document text
    • https://cdn.sqhk.co/nugubirudif/dgcEbpO/70723844858.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/rudelazifizuvo/korikakuzuxoveninaripu.pdfIn PDF document text
    • https://s3.amazonaws.com/wejuvono/97346691602.pdfIn PDF document text
    • https://s3.amazonaws.com/nawosineromigi/fibezijekinabijotukugexib.pdfIn PDF document text
    • https://s3.amazonaws.com/foneniz/fosironola.pdfIn PDF document text
    • http://nokejufesuw.atwebpages.com/business_productivity.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_off0000d088.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD088 5608 bytes
SHA-256: 3eb7106918f8ea26c30a3f4c72006954baeb4aff1e2f65130cb3a2c0d67871c5
font_01_sfnt_off0000e379.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE379 9524 bytes
SHA-256: a0ebfb99bbca9ef7a0ddda9e2f6a9a901b4ba42e6ee2fb48faa58e42c74fcfe9