Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e2169826eab81ab…

MALICIOUS

PDF

134.0 KB Created: 2021-06-05 17:34:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 1592e7ca92490a08d83ea5805a500512 SHA-1: 5bb1941834a0394a7e973d9981a863906aed2828 SHA-256: 8e2169826eab81abc1287977fe21a514f9436ed9133f1cb720e00870301e8aac
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.001 PowerShell

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious. It contains heuristics indicating it's a link farm and a lure to execute commands via the clipboard. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a URL that appears to be a lure for 'create bootable usb mac disk utility el capitan'. The presence of a clipboard command lure suggests an attempt to trick the user into executing arbitrary commands, likely to download and run a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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=create+bootable+usb+mac+disk+utility+el+capitan PDF link annotation
    • https://nuresoxak.weebly.com/uploads/1/3/1/3/131380504/c4b4ebfad4dbd.pdfIn PDF document text
    • https://digavonuvuveg.weebly.com/uploads/1/3/4/8/134851043/gululatipuladokal.pdfIn PDF document text
    • https://batigagonu.weebly.com/uploads/1/3/4/7/134774980/8995995.pdfIn PDF document text
    • https://lubikumak.weebly.com/uploads/1/3/1/4/131453733/85a2a36d3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420747/normal_603655a7ab70e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4474723/normal_5fc7cb1e4c23e.pdfIn PDF document text
    • https://wolunogejafijut.weebly.com/uploads/1/3/4/6/134649672/d838f.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://suniger.pbworks.com/f/zumdahl_chemistry_9th_edition_answers.pdfIn PDF document text
    • http://lufokomarib.pbworks.com/w/file/fetch/144477843/makkar_ielts_writing_task_2_2021_with_answers.pdfIn PDF document text
    • http://wejojixi.pbworks.com/f/passive_voice_past_continuous_tense_exercises.pdfIn PDF document text
    • http://sovafiben.pbworks.com/f/angular_2_tutorial_for_beginners.pdfIn PDF document text
    • http://zevatirupura.pbworks.com/w/file/fetch/144585969/lumakiwuguzesewosafi.pdfIn PDF document text
    • http://puxivir.pbworks.com/f/lawewatemuwamuvusumep.pdfIn PDF document text
    • http://sepaxebi.pbworks.com/w/file/fetch/144413406/32757392872.pdfIn PDF document text
    • http://kufujibumufa.pbworks.com/w/file/fetch/144411645/how_to_connect_vizio_wireless_sound_bar.pdfIn PDF document text
    • http://mogulazedub.pbworks.com/f/82967996490.pdfIn PDF document text
    • http://negovijalulu.pbworks.com/w/file/fetch/144412809/79771687594.pdfIn PDF document text
    • http://sutodoromar.pbworks.com/f/89914627747.pdfIn PDF document text
    • http://nubuzefi.pbworks.com/f/povirinimotaboba.pdfIn PDF document text
    • http://mifimoruzuwo.pbworks.com/w/file/fetch/144451602/how_to_reset_code_on_hotel_safe.pdfIn PDF document text
    • http://xuruzinijub.pbworks.com/w/file/fetch/144423816/kizubodoxeb.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e4c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C7 74360 bytes
SHA-256: 390789e3408c860850ec16f8eb0e02a73108775ebb4379daecad4a160c6e1576
font_01_sfnt_off0001bf03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BF03 5432 bytes
SHA-256: 3d7bf027174019451f7e049d16ba145a3247ce3ecbfab9f58e715b060be702fa
font_02_sfnt_off0001d161.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D161 10168 bytes
SHA-256: 43bfa0ecaa25e58f1263c5ec38e1e317dcef70213f33fb43a66e2edbeeb01831
font_03_sfnt_off0001f489.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F489 16092 bytes
SHA-256: b5f0b32f6543351256b73815f81a040120bd033010e1d2e1258d4bc00aa53fb6