Malicious PDF — malware analysis report

Static analysis result for SHA-256 61ee55fc38223ecb…

MALICIOUS

PDF

88.1 KB Created: 2021-03-20 17:20:20 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 26947604d18d0852a463ffad7718681f SHA-1: d5141c4737ddd3431d0da86f03ba29894bae9643 SHA-256: 61ee55fc38223ecbb5b91f991794cd171333f426ae95e34ec02c1fbfd5972710
186 Risk Score

Malware Insights

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

This PDF document was flagged by multiple heuristics and a machine learning classifier as malicious, specifically identified as a phishing trojan by ClamAV. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or redirection scheme to malicious sites. The document body, though truncated and partially corrupted, contains a title related to mathematical inequalities, likely a lure to disguise the malicious intent of directing users to external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://lozipotod.ru/strik?utm_term=solution+set+of+inequality+5x-3+3x%252B1 PDF link annotation
    • https://vimititop.weebly.com/uploads/1/3/4/3/134339659/dixevubin_widimewogefit_senusigiramo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413243/normal_5fd1e0f2c24f2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376362/normal_601bac91e52a2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421970/normal_5ff2f43198430.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474719/normal_5fd8b7d49904a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4418985/normal_5fdfcfa929ee4.pdfIn PDF document text
    • http://tiwikif.22web.org/wix_bookings_add_ons.pdfIn PDF document text
    • https://pabebubi.weebly.com/uploads/1/3/2/6/132695301/lidoromaneru.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370780/normal_603012fda74e1.pdfIn PDF document text
    • https://mogorabijeruli.weebly.com/uploads/1/3/1/3/131380728/53e89e7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374198/normal_602bff2edcfba.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485322/normal_6021cbf7552e5.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/ddb22141-e8ed-4a5a-b1aa-0e7975c1173a/tipos_de_expresin_oral_que_existen.pdfIn PDF document text
    • https://e86c6366-0652-46cb-9e1f-5633a133dba9.filesusr.com/ugd/510a18_08e697e0557540b6b4b29bb308bf43e5.pdf?index=trueIn PDF document text
    • http://doputokodopesib.rf.gd/buderus_plan_heizkrper.pdfIn PDF document text
    • http://kepijemimubu.rf.gd/international_financial_management_jeff_madura_solutions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/99d6f335-8c98-48f3-834c-4f7559ad3ad7/bodebogovinolikikagarom.pdfIn PDF document text
    • https://562c2315-396f-49d1-9e45-1236e049cb13.filesusr.com/ugd/ec0012_e393f6816b0d4a699db300b6d55337c6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/257cc151-a3b1-46f2-b097-043b6261b5a9/naval_correspondence_manual_2010.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_off000115fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115FA 5436 bytes
SHA-256: 949487ef2eae21ebe0c40557924064892c2a7cebe46c1a273e7c9484ea671e46
font_01_sfnt_off000128ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128BA 11868 bytes
SHA-256: f5f1072b723e8b3472e2fa4553d48d6728760384c6b7cf4a3d2962447110a329