Malicious PDF — malware analysis report

Static analysis result for SHA-256 28d1e28f51fa2a32…

MALICIOUS

PDF

80.0 KB Created: 2021-05-22 02:46:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 9b4f1491dc53df1e3fc74805132a9a5e SHA-1: e08f89fb2beb79e546cb3cc2ea432771baf5c8e3 SHA-256: 28d1e28f51fa2a32ec34506845c156116151fd88a1c42c7f899c3392d733f951
194 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 and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://dafemum.ru/strik?utm_term=ejercicios+de+matematicas+para+segundo+secundaria+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4484997/normal_60519e4010b9c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384828/normal_605c24b6ed1a6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420438/normal_602c8de61cd0f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384035/normal_6021c0467347b.pdfIn PDF document text
    • https://padudarudiloga.weebly.com/uploads/1/3/4/7/134714427/vunekakomef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460982/normal_6024b554dcbde.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388156/normal_5fe6412b776fc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406466/normal_604040a0268ec.pdfIn PDF document text
    • https://duzopuxezofuj.weebly.com/uploads/1/3/1/3/131382696/40aecce37b2.pdfIn PDF document text
    • https://kadeniki.weebly.com/uploads/1/3/4/0/134097858/pofufewokupag.pdfIn PDF document text
    • https://tubolapibakosi.weebly.com/uploads/1/3/4/8/134872187/70a637e2e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459062/normal_60300f7dd0a9b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413121/normal_6040bbf7928b5.pdfIn PDF document text
    • https://falusawo.weebly.com/uploads/1/3/6/0/136084102/wirabukezewenif_lunul.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460968/normal_606aed2bd756f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4406782/normal_5ff90530c7f12.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/piwanisaj/minecraft_trial_for_pc.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98b680c6-6548-4c4a-a674-2d402173e08e/how_to_get_a_baseball_bat_in_gta_5_online_xbox_one_2019.pdfIn PDF document text
    • https://s3.amazonaws.com/jeduzizonox/meaning_of_report_writing_in_marathi_language.pdfIn PDF document text
    • https://s3.amazonaws.com/rowubunak/bootstrap_contact_us_form_w3schools.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eda13627-dfd2-4c80-bcb7-287a22f1269a/74175656522.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e74b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE74B 5356 bytes
SHA-256: 4a3db37df542549fb6bf1c9fb88f121aeef751ccbb7d58d398cf3da0a660f6ab
font_01_sfnt_off0000f96d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF96D 11988 bytes
SHA-256: 46cef0eea625cbab8ba8b6b3f20399cc5b23f5c8f204d884570a658d29cd02f6
font_02_sfnt_off0001224f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1224F 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2