Malicious PDF — malware analysis report

Static analysis result for SHA-256 19774c99410c0ddb…

MALICIOUS

PDF

81.0 KB Created: 2021-09-15 17:59:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: efa69c19d03da2102ce5f2fb356013f9 SHA-1: 973c735803a1025c937ef3d47ee8065a56ca2c1d SHA-256: 19774c99410c0ddbd82c0005e111b39c21031d538ddc8817864bfe4a43f51018
166 Risk Score

Malware Insights

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

The sample was detected as a phishing trojan by ClamAV and flagged by an ML classifier. It contains numerous external URIs, many of which point to PDF files hosted on distinct domains, indicating a link farm. The heuristic 'SE_LOLBIN_RUN_COMMAND' suggests the presence of command-line execution indicators within the document text, likely related to the exploitation of the PDF format. No scripts were extracted, but the overall structure and detection indicate a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://jocafoto.com/fotos/file/81344799349.pdf In PDF document text
    • http://rayocazar.com/images/elfinder-1.1/files/file/68478321215.pdfIn PDF document text
    • http://csc0311.com/userfiles/file/20210913130510_wlkx7d.pdfIn PDF document text
    • http://litho-and-co.fr/ckeditor/upload/files/36810208829.pdfIn PDF document text
    • http://portalpr-b2b.es/img/user//file/_0698899001630686337.pdfIn PDF document text
    • http://car-zone.sk/data/data/file/zowadezowaxerolabom.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/76914018845.pdfIn PDF document text
    • http://stringquartet.biz/web/images/fck/file/18661549563.pdfIn PDF document text
    • http://picart-personal.pl/fckupload/upload/file/72019317499.pdfIn PDF document text
    • http://hanauhrova.cz/files/purudukomuzusofepowuxabu.pdfIn PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/4625551482.pdfIn PDF document text
    • https://vitanov.rs/files/47694278716.pdfIn PDF document text
    • http://architettoangeli.it/userfiles/files/3429473227.pdfIn PDF document text
    • https://sonerofset.com/userfiles/file/38527182796.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/9150237531.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///85404567345.pdfIn PDF document text
    • http://raczcsalad.hu/files/18204177836.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/wumewefarol.pdfIn PDF document text
    • https://perfectprojects.ro/userfiles/file/79863594834.pdfIn PDF document text
    • http://cpghollywood.com/userfiles/files/67843530223.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210914_03EF992F3CA31163.pdfIn PDF document text
    • http://qdcmd.com/data/files/36148658826.pdfIn PDF document text
    • http://ketoanantamhcm.com/uploads/files/rafaso.pdfIn PDF document text
    • http://tomgiongvip.com/uploads/files/file/korupexuxejo.pdfIn PDF document text
    • http://ketoanantamhcm.comIn macro / runtime command snippet
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=how+to+transfer+pictures+from+android+to+laptopPDF 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_off0000d38f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD38F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eba1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA1 18992 bytes
SHA-256: c7f0e55cdc0e709388cc2961e74805d7389d5611c5ce6347fac43990394f8faf
font_02_sfnt_off00011c53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C53 10956 bytes
SHA-256: 7bf7d1a747ef9624063018a35accc1a7b9cda8ec1fdc8bd66c88cc0123db3b3a