Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa77f9e65bbb41d7…

MALICIOUS

PDF

72.6 KB Created: 2021-09-27 10:25:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4b29f4e78da0c22b22391ecab1538ca1 SHA-1: ebf5ae804987995039531d1bfe89be2de6dacdae SHA-256: aa77f9e65bbb41d7f335b3d7459de6f3929f3d18b30f963c4de7e4f169535071
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains and are likely part of a link farm designed to redirect users to malicious content. The presence of 'cmd.com' in the document text suggests an attempt to execute commands, potentially exploiting vulnerabilities within the PDF reader.

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://sabunwangi.com/contents/files/nuxosimo.pdf In PDF document text
    • http://cukrarska-vyroba.cz/UserFiles/File/22676198328.pdfIn PDF document text
    • https://www.bbmnetlicitacoes.com.br/cms/ckfinder/upload/files/kakis.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/67142977768.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/25fgilqp1kajlm9ku7blmv3rhi/9486376220.pdfIn PDF document text
    • https://it-remarketing.pl/app/webroot/media/files/wifamuxop.pdfIn PDF document text
    • http://qdcmd.com/data/files/moteb.pdfIn PDF document text
    • http://frankifoto.com/uploads/pages/files/wadigirutorar.pdfIn PDF document text
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/nejevanopugafezinuniwe.pdfIn macro / runtime command snippet
    • http://thangmayedex.com/webroot/img/files/83652916060.pdfIn macro / runtime command snippet
    • http://daltan.hu/userfiles/file/23084866481.pdfIn PDF document text
    • https://lodoshosting.com/calisma2/files/uploads/34610794012.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/wevaxufi.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/sedonigifiwivaman.pdfIn PDF document text
    • http://kedehg.com/ckfinder/userfiles/files/60190812422.pdfIn PDF document text
    • https://esofagopisa.it/userfiles/file/76753460065.pdfIn PDF document text
    • https://tjp2-hotlink-j3t.com/contents/files/vazifarofusar.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/nuruwebapa.pdfIn PDF document text
    • http://ozdoby-betonowe21.pl/Upload/file/78095076477.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/65191698314.pdfIn PDF document text
    • https://impactmediaresources.com/userfiles/file/63552890251.pdfIn PDF document text
    • http://jsushibrea.com/uploads/files/vozazivaratutipil.pdfIn PDF document text
    • http://frankifoto.com/uploads/pIn macro / runtime command snippet
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+send+image+in+push+notification+android+using+firebasePDF link annotation
    • 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://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_off0000b27c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB27C 11336 bytes
SHA-256: 9af3213ad3ba80e1bfea160e1e5815f847f54810930988e47a7586592755858a
font_01_sfnt_off0000cc90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC90 17688 bytes
SHA-256: 04f58212cccd648659eb0d8505d71ef32d0230c7a586bfe2236bd307308cadf2
font_02_sfnt_off0000fa2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1