Malicious PDF — malware analysis report

Static analysis result for SHA-256 77cb9761564689e1…

MALICIOUS

PDF

85.4 KB Created: 2021-06-07 05:48:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 1243c187d94bcab0155e8106fa22a28e SHA-1: d69a1694651a783f926721cd967cc5f4a7261000 SHA-256: 77cb9761564689e1014c7618f5780e75c5c989d05b4123de34d567616b039f8d
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 0.9996

Heuristics 6

  • 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.
  • 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://medvor.ru/pbw?utm_term=syllabus+of+bihar+b.ed+entrance+exam+2020 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4477921/normal_603e9db2e67f4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454180/normal_603e84c634e24.pdfIn PDF document text
    • https://zofoneparadi.weebly.com/uploads/1/3/5/3/135341866/9299993.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415292/normal_6018c311ceadb.pdfIn PDF document text
    • https://witowufagefalob.weebly.com/uploads/1/3/0/7/130738848/88114.pdfIn PDF document text
    • https://milalidit.weebly.com/uploads/1/3/1/4/131437162/kudomafilav.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369327/normal_603eb2553877e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367273/normal_602b2dc65b4d3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457848/normal_60646e48e8f73.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454286/normal_5ff6b9aa23fe0.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
    • http://fedorahosted.org/lohitIn PDF document text
    • https://uploads.strikinglycdn.com/files/eabce383-8bf3-4982-92fa-9bc6eac7ae82/winston_salem_aau_basketball_teams.pdfIn PDF document text
    • http://wiwedano.pbworks.com/f/72433586748.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cdfef46f-cf26-423b-ba20-5986dfa3c91d/how_to_put_screwdriver_bit_in_black_and_decker_drill.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4c214c6-bfc7-4157-bd98-5cbeec4df5d6/45005072027.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5580e4a2-a42a-4b6e-940e-49a7d615deaa/apple_time_machine_router_speed.pdfIn PDF document text
    • http://wuwolufit.pbworks.com/w/file/fetch/144659139/i_fiori_del_male_film_streaming.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/14f43c7f-6b00-4f55-96e7-cb370041520a/new_construction_home_cost_estimate_sheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/36e2b944-70fe-40d5-9fe0-4d409e0c34dd/gluten_free_dairy_free_cookie_recipes_peanut_butter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/325bcf2c-a4ff-462d-8271-75387b3a0d63/92535483724.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e50126fa-a78b-4f16-bd6d-601f3928ea94/waterpik_water_flosser_hose_repair.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e36b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE36B 5864 bytes
SHA-256: f1f42aaedeacb3d84f9dc5fa3ea53600665cbc477056473d659c2a5a0446238c
font_01_sfnt_off0000f737.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF737 10604 bytes
SHA-256: f06f5994c006497dc236fc045f4030f2a71b89843e82c2456b61907b64687600
font_02_sfnt_off00011b6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B6B 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3
font_03_sfnt_off0001296a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1296A 9364 bytes
SHA-256: 745a428b5769d66f59805e6e87f2e1dd0dfc0034bf981ccaf086feb9ae0d6a92