Malicious PDF — malware analysis report

Static analysis result for SHA-256 b380632f71d2e87e…

MALICIOUS

PDF

115.3 KB Created: 2021-06-10 07:01:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: c8aeda586a64e259d41de172108c40d7 SHA-1: 697768683cd76918905e176aa155a3b35a40c5e9 SHA-256: b380632f71d2e87e3ef2d8aed28e091a05e3eb961ebd9d4916320e43a9b2f596
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external links, many pointing to disposable hosting, suggesting a link farm or phishing operation. The embedded document body text, though garbled, contains a reference to 'Oxford discover grammar 5 answer key', indicating a lure to entice users to click on the malicious links. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://crewmak.ru/pbw?utm_term=oxford+discover+grammar+5+answer+key PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4393026/normal_6051e09a2b43f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4458413/normal_5fcb6dc47326e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4469863/normal_6001458052d66.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4380237/normal_6008848a641bd.pdfIn PDF document text
    • https://mesubepivugegej.weebly.com/uploads/1/3/2/6/132682347/9983522.pdfIn PDF document text
    • https://xuwudobuxu.weebly.com/uploads/1/3/2/6/132682441/xomuxaxaze_dusanukadabepum.pdfIn PDF document text
    • https://vamepaxokuwi.weebly.com/uploads/1/3/5/9/135959455/sunomalajidu_dububejujatituf_wapozopivub_kakorugimasojaj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402519/normal_5fe8a53c158c7.pdfIn PDF document text
    • https://sejirefado.weebly.com/uploads/1/3/4/6/134682993/3543b14253.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424040/normal_6028a65196a8d.pdfIn PDF document text
    • https://pukibasobudez.weebly.com/uploads/1/3/1/3/131379944/vivovivaxazij-vofedisudiw-nupaj-fegedugijunaf.pdfIn PDF document text
    • https://vugogirofezufus.weebly.com/uploads/1/3/4/3/134355312/1341617.pdfIn PDF document text
    • https://porujigiwafixuf.weebly.com/uploads/1/3/4/3/134373975/866efd1.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/8786f208-1b81-4507-b150-b463e22fb3a7/3026880533.pdfIn PDF document text
    • http://zabodovojif.pbworks.com/w/file/fetch/145016253/90076829576.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4cd9861e-efb7-41f4-b997-d890b31b5df7/80994494385.pdfIn PDF document text
    • http://jininude.pbworks.com/f/download_cheat_sonic_dash.pdfIn PDF document text
    • http://mudowomuxexo.pbworks.com/f/sokanub.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/923e2da4-5536-46bf-b9e3-dbe4dabcb4d0/tajudanolupujuvikufox.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ee8e47f7-bccf-412e-850a-4a916508473e/govopevagoxovar.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00016ba6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16BA6 5848 bytes
SHA-256: 79e0fdcc0d44609b9c9f18b49b96e6452abcf197c99083cd85657e818e31128e
font_01_sfnt_off00017fa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17FA8 12416 bytes
SHA-256: ee9b5bea729daf0b245cdb19799896cc8cfaee51e198c665c5a65cecd5d6c180
font_02_sfnt_off0001a7da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A7DA 16140 bytes
SHA-256: 00468df452218f546d59995a7cf9b4297092e2fd476dbd2f6ce79846bd051107