Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6a285c53cb9d28c…

MALICIOUS

PDF

73.5 KB Created: 2021-03-17 00:59:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c0963d1123065960421f10b8dc11b2b6 SHA-1: e15a7779cab1b74bcc3f3dbe5c51b33f44da7260 SHA-256: f6a285c53cb9d28c9a185657878c073e5559e35ddd79f04e62181c5cadb99fb3
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to Weebly-hosted PDFs, suggesting a link farm or SEO spam operation. One of the primary external URIs, https://nipisod.ru/strik, is likely a malicious redirection or phishing endpoint. The document body, though heavily obfuscated, appears to be related to search result content, reinforcing the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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/strik?utm_term=the+courage+to+be+disliked+amazon+uk
    • https://jowopuvuramikir.weebly.com/uploads/1/3/5/3/135313070/juxipitirasarog_kivoveteta_jawuwafofebis.pdf
    • https://jiwejezagaxu.weebly.com/uploads/1/3/5/3/135325467/votum_ludobofap.pdf
    • https://mefupawex.weebly.com/uploads/1/3/4/3/134317460/1911293.pdf
    • https://pukaxixuzex.weebly.com/uploads/1/3/4/4/134492253/4d4bf5.pdf
    • https://cdn-cms.f-static.net/uploads/4383573/normal_6019ff835c13d.pdf
    • https://juzubuju.weebly.com/uploads/1/3/4/7/134703155/66c5b77f31e9f1.pdf
    • https://cdn-cms.f-static.net/uploads/4481422/normal_601a74e27a0aa.pdf
    • https://cdn-cms.f-static.net/uploads/4417325/normal_6011ec4e42e15.pdf
    • https://nerupeke.weebly.com/uploads/1/3/1/4/131483009/3115752.pdf
    • https://static.s123-cdn-static.com/uploads/4404959/normal_5ffdb53288343.pdf
    • https://cdn-cms.f-static.net/uploads/4418984/normal_5fd7b19d4d8b8.pdf
    • https://static.s123-cdn-static.com/uploads/4412768/normal_600839b4431a0.pdf
    • https://semazuxogevagox.weebly.com/uploads/1/3/4/0/134017751/mifolus.pdf
    • https://static.s123-cdn-static.com/uploads/4421354/normal_5feb4f15e8cb5.pdf
    • https://static.s123-cdn-static.com/uploads/4389571/normal_5ffa89dceff4d.pdf
    • https://cdn-cms.f-static.net/uploads/4388412/normal_6030202ed2177.pdf
    • https://bixowupe.weebly.com/uploads/1/3/1/4/131409305/zixibujabezos.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/19501235-83d8-484e-a972-a9ed28c94257/pokemozajimofulixu.pdf
    • https://uploads.strikinglycdn.com/files/8480dd4f-e8ff-4464-9b94-e670f0f5f67f/how_much_does_it_cost_to_get_certified_for_eyelash_extensions.pdf
    • https://uploads.strikinglycdn.com/files/b1b95d90-06a4-4067-b042-9f3b6d6d4f00/pearson_edexcel_igcse_chemistry_student_book_answers.pdf
    • https://uploads.strikinglycdn.com/files/c2dc214f-64e8-46bb-aeab-0ba53384a497/2150775627.pdf
    • https://uploads.strikinglycdn.com/files/11dfc8c4-f98f-4728-b6d8-a55df64183b6/88463527893.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de5f.bin
bade5d05df50ca343e952ee0f5781a4597ae9724f1f8ae6c2f52a4635548e9ee
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE5F 5556 bytes
font_01_sfnt_off0000f11e.bin
ed9fd8f93d45e9e81d315bb9d75f3b8103a05f6e655b1a63dad2affce164ef80
pdf-font-stream PDF embedded font (sfnt) at offset 0xF11E 11004 bytes