Malicious PDF — malware analysis report

Static analysis result for SHA-256 258da3434e48196f…

MALICIOUS

PDF

78.5 KB Created: 2021-04-04 06:59:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 7082ab87212e68be232c8cfb5db4d762 SHA-1: 6274b906d84a61204676590baeb714a3b93e6fe3 SHA-256: 258da3434e48196f2bac689c63e51191adf777e6b1515a408ec189028429ec07
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains an embedded URI pointing to 'nipisod.ru', which is likely a phishing or malware distribution site. The document body is heavily obfuscated but contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, further supporting the lure of a downloadable document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://nipisod.ru/award?keyword=direito+penal+parte+especial+bitencourt+pdf+download PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4443812/normal_600511cc20833.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470028/normal_60492c2a5cc42.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4452853/normal_5fed74bd78d23.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447646/normal_6035cd37ce7b7.pdfIn PDF document text
    • http://zukesijinizik.mywebcommunity.org/fapidaretu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483331/normal_5fdc522ac26e7.pdfIn PDF document text
    • http://talajifit.mywebcommunity.org/attestation_d_hbergement_la_banque_postale.pdfIn PDF document text
    • http://pinezotamex.getenjoyment.net/82831251592.pdfIn PDF document text
    • http://tiluvopira.medianewsonline.com/sutokaxobatuvili.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488806/normal_601570c8e6ae6.pdfIn PDF document text
    • http://joteruzawareba.iblogger.org/insulation_for_sheet_metal_duct.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/wizidimawag/afcat_exam_form_2018.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/28a7975a-d873-49f1-9ade-7e13407c5d5f/murray_push_mower_bagger_attachment.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/78765100-45c9-4179-af7a-8f6dea3f7609/bosch_800_series_washer_detergent_tray.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b9e30cc0-6cac-444d-9363-bebe666cd501/jemizakedobisemutaxalif.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/85bfe040-1941-4cd9-9417-55bd5967c70b/nevomiwe.pdfIn PDF document text
    • http://waxefikerulun.epizy.com/what_does_delta_h_represent.pdfIn PDF document text
    • https://s3.amazonaws.com/fejatepudopito/gepewugad.pdfIn PDF document text
    • http://powuruzi.epizy.com/21604167363.pdfIn PDF document text
    • http://fexunipeguzizu.rf.gd/39792151460.pdfIn PDF document text
    • https://s3.amazonaws.com/difigomisosak/miss_usa_2017_question_and_answer.pdfIn PDF document text
    • http://rozafibadajowo.epizy.com/23889033951.pdfIn PDF document text
    • https://s3.amazonaws.com/kuxuxemu/29337181858.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/383b3ca0-2524-4570-8a7a-a711124c31c9/jelajival.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF0E 6440 bytes
SHA-256: 629123bfde0685c5f69bbdd27ec008bde0224d5c30af1dabb990f6ee33ea778e
font_01_sfnt_off0000ef02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF02 5380 bytes
SHA-256: 0902d311aaa159a53127f68944c822c2e5ec9b59e29540fff1d522528d3b8e13
font_02_sfnt_off00010169.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10169 13240 bytes
SHA-256: 8ed1cd5be2539c718788a9497bab744e32d3724ece0adb8401c7c55be302e9d3