Malicious PDF — malware analysis report

Static analysis result for SHA-256 c27fad9fd8295153…

MALICIOUS

PDF

73.9 KB Created: 2021-03-30 18:20:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 983d3cb9223876f14c044128952c26de SHA-1: 6bc1f0bc9bee450a1618195110f97fae31200052 SHA-256: c27fad9fd8295153c4b7f47fb95d3edfa51f5d99f6cadd247e4d2b15284dfc8e
186 Risk Score

Malware Insights

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

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 6

  • 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 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://nipisod.ru/wix?keyword=molecular+structure+worksheet+1+answers PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4369310/normal_602a35814388b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475861/normal_601160e916e66.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424043/normal_6032b85a4674c.pdfIn PDF document text
    • https://cdn.sqhk.co/fukonovum/dvgdhaT/history_channel_show_vikings_cast.pdfIn PDF document text
    • https://cdn.sqhk.co/fofotixoz/hfQgehb/caterpillar_chunky_sneakers.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478408/normal_6022eb3181aec.pdfIn PDF document text
    • https://cdn.sqhk.co/luxixumogez/7NJPtFp/how_to_learn_javascript_faster.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464732/normal_600c46321b38b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492240/normal_5fd703ba044ec.pdfIn PDF document text
    • https://cdn.sqhk.co/posaleren/iijbpRT/visaxi.pdfIn PDF document text
    • https://cdn.sqhk.co/definuseju/gcjhdjc/nail_biting_deterrent_cvs.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403806/normal_603538ee932f0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403808/normal_6011efa519c01.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://011f98f8-b45f-4578-a2fd-466b530f7845.filesusr.com/ugd/74e905_ca9f602ce343470e86c6e6d955585afd.pdf?index=trueIn PDF document text
    • https://45dcde1a-aed5-4138-b95e-a0f768a283bf.filesusr.com/ugd/89441e_8bcb7d0d69a84aec8c3b527c5927ea36.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/8344f426-d70f-487f-9989-4a9585b061db/ezgo_marathon_parts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/28a6354c-b881-4e25-9216-3b343ee1f082/surat_juz_amma_bahasa_indonesia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ca1d81e1-dbea-4c98-b41f-8be3fa9361c8/79981488367.pdfIn PDF document text
    • https://a3de454e-1598-42bb-a259-4eb69c42f179.filesusr.com/ugd/fb5067_8b65575cf7534a558469f8e3b10413dc.pdf?index=trueIn PDF document text
    • https://1580f21e-fc75-4350-9669-3be8b7525729.filesusr.com/ugd/eff6cf_edd034ef69d941709a823d4dc745347f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/55625a19-736b-460f-87c7-391c17a8e2c2/jack_reacher_tv_series_season_2.pdfIn PDF document text
    • https://95fbbc11-640f-4658-acdf-6e09da746871.filesusr.com/ugd/e42ee3_692502985c5f4c5ca64080122692eede.pdf?index=trueIn 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_off0000e2b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B3 5100 bytes
SHA-256: 717b1c8cacf5f3375a23e1dda5a47cb6aa289269f9a9c923960c42e032a9dc95
font_01_sfnt_off0000f426.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF426 11112 bytes
SHA-256: 854e86da7c2b8a0fa5e0f2fad07cfcb3748129f59990b8383464e654c27fe1ff