Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ba84b13d3367d2…

MALICIOUS

PDF

80.7 KB Created: 2021-06-05 17:33:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 9ddf889fb5fda71b5aaea50e75d22301 SHA-1: 4750fe8f690162e024f6313556b37b6169648ac9 SHA-256: 81ba84b13d3367d2c8fadd7c2b1d85fb5bbf86189f42715170871ff7ef947076
126 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cructi.ru/pbw?utm_term=healthy+mashed+cauliflower+instant+pot PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4450038/normal_601b73cd5a126.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450519/normal_60504614e8046.pdfIn PDF document text
    • https://jitoxazenop.weebly.com/uploads/1/3/4/5/134588357/3a98f2a4e96.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445129/normal_604fec66eed91.pdfIn PDF document text
    • https://memesuxiti.weebly.com/uploads/1/3/4/6/134635319/8365333.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386836/normal_60ba61d0cb740.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4474988/normal_60b61fa11f684.pdfIn PDF document text
    • https://nusavudusegi.weebly.com/uploads/1/3/4/4/134444144/3194108.pdfIn PDF document text
    • https://repugonajipivup.weebly.com/uploads/1/3/0/8/130814926/bisetur.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448536/normal_6014dc359db52.pdfIn PDF document text
    • https://wupupuredizuso.weebly.com/uploads/1/3/4/8/134894828/wukefejimusav-pibisoxirepatun-papinoguliseze-neluvagagirusi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459341/normal_6013765d408de.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/d3021337-5bc0-4257-aca8-9c04ce8f5e01/valor_esperado_y_varianza_de_una_variable_aleatoria_discreta_ejemplos.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7011a070-34e8-4864-9cad-0fd70b24baaa/gupopojirexi.pdfIn PDF document text
    • http://magogopowo.pbworks.com/f/defubijoba.pdfIn PDF document text
    • http://nusuwoxub.pbworks.com/w/file/fetch/144414738/velocity_time_graph_worksheet_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/97bc893a-9f5e-4b5c-b222-836a6f5adf2d/how_to_pair_altec_lansing_bluetooth_speaker_to_iphone.pdfIn PDF document text
    • http://paderukut.pbworks.com/f/libros_de_artes_marciales.pdfIn PDF document text
    • http://joraxakegeg.pbworks.com/f/14380591285.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c02b08eb-e970-4905-9792-280d20a6a25c/50746058079.pdfIn PDF document text
    • http://fixunomavow.pbworks.com/f/watirabo.pdfIn PDF document text
    • http://wuxikadafi.pbworks.com/f/zefofobevakatifuwevix.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE867 5552 bytes
SHA-256: 5f67340b091c5e4f8425ca12a44dc8db614d211059b99c5c01ae30c54959cca8
font_01_sfnt_off0000fb31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB31 10776 bytes
SHA-256: d5668999f49770add7b0514985541ff369d8b6d4226c829c34a3c98f85148725
font_02_sfnt_off0001204e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1204E 16092 bytes
SHA-256: e9fe716c2abc985b12a899a49d5539e4e8be1b56d50c083b30290d85a2a7c848