Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfc557070352dc9a…

MALICIOUS

PDF

72.5 KB Created: 2021-06-12 09:13:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: ae72aec3657f680bbd348212e6c2224b SHA-1: cd4ee262fccf7e1b3e079e0ed48129a503c10aa7 SHA-256: cfc557070352dc9a061a2262bc19e2d0ff70d50d4a24a0aeca4c1d78e7eabfbb
126 Risk Score

Malware Insights

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

The PDF contains an embedded URL that redirects to a link farm on disposable hosting, masquerading as 'calculus exercises with answers'. This URL is likely used to host phishing content or distribute further malware. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://ketchas.ru/pbw?utm_term=calculus+exercises+with+answers PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4410002/normal_6060a21174f30.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413850/normal_5fef6df2148bd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454422/normal_5fe112db67f9f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475208/normal_601a3ab3b8e98.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454977/normal_6056348767e86.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454668/normal_5fd62f6355eb5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451369/normal_5ffdb7cfba135.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484997/normal_60bc5ee60bdc7.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4418167/normal_60b7649d1f537.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383794/normal_604478618be14.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382189/normal_606e21c8c5233.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483624/normal_605956a1b56ba.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/ee77f25d-130e-4977-a284-14960df05369/nafajixu.pdfIn PDF document text
    • http://japomajuxire.pbworks.com/w/file/fetch/144467121/beck_depression_inventory_2_scoring.pdfIn PDF document text
    • http://fisagibop.pbworks.com/w/file/fetch/144938724/rimudezekilalexodudi.pdfIn PDF document text
    • http://wemilamozede.pbworks.com/f/how_to_open_files_on_ipad.pdfIn PDF document text
    • http://vatojorisa.pbworks.com/w/file/fetch/144436854/bhakti_gana_dj_song_video_mein.pdfIn PDF document text
    • http://gibuwodebu.pbworks.com/f/enriques_journey_quotes_about_immigration.pdfIn PDF document text
    • http://xawasesofe.pbworks.com/f/mere_sathiya_sun_payal_ki_runjhun_mp3_song_download.pdfIn PDF document text
    • http://gosirata.pbworks.com/w/file/fetch/144668268/17046560707.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/05bd4a78-abbe-45c9-9e97-57d15cc00fee/xofumijodokotol.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2ccdd3bd-b34c-45fd-b611-37c9731fecb7/nordyne_furnace_troubleshooting_guide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7024b82b-840a-4f5e-9d3c-27b20caa1ca9/parrot_in_the_oven_chapter_10_quotes.pdfIn PDF document text
    • http://gamaxidad.pbworks.com/w/file/fetch/144620259/rafajagoripiwunog.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_off0000dc14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC14 4952 bytes
SHA-256: a58111a6c14f7e6136b4c220753b5987a0320e75114d6d148483a2f140cc5871
font_01_sfnt_off0000ecf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF3 11572 bytes
SHA-256: 4dc6bcc766f5e6c29f63439798063432bb5f282306dd735c46e0f0a657ded41d