Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9f9b8d582b50c44…

MALICIOUS

PDF

78.0 KB Created: 2021-09-04 17:57:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 76a0042fc2a9608e2680f9fc0f293e60 SHA-1: 3a2fdd6a31c342f8829875e3d61f4136ccb39951 SHA-256: b9f9b8d582b50c44969f8c02c5d0f39c639d88a3e9d19178d5a955634458125d
124 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan. Static analysis revealed it functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a pattern of using small PDFs for link farming on disposable hosting, and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM suggests these links may be hosted on compromised CMS upload directories. The primary purpose appears to be redirecting users to external sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.3709

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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
  • 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 http://akinmedical.com/uploads/file/fanuto.pdf In PDF document text
    • https://cristalensi.com/public/File/koreramefavifer.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/20733933529.pdfIn PDF document text
    • https://mk-sito.it/uploads/file/48071971361.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16094585a11cfe---salexatinoniwamemogo.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/mexowatixobaz.pdfIn PDF document text
    • http://xn--h49avwqct32ewe967crscpsaz7d.com/ckupload/files/20713054886.pdfIn PDF document text
    • http://ihdbd.org/upload/files/26510145315.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/161196b7f75c23---befukiwopuduluvimamoz.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d9c7112f800---tisaxix.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/87444860509.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/bc0r2u5o2psaoa1dljfd47prs0/80672041032.pdfIn PDF document text
    • http://global-leasing-management.com/uf/file/24202532529.pdfIn PDF document text
    • http://domosplast.hu/files/file/kedokodekaredu.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608a3520b637b---19707048509.pdfIn PDF document text
    • http://somsit.com/ckfinder/userfiles/files/79833225177.pdfIn PDF document text
    • http://kingsbrite.com/kingsbrite.com/userfiles/file/68866903934.pdfIn PDF document text
    • http://nexxosrealty.com/userfiles/files/pajofosadifofizavawezegi.pdfIn PDF document text
    • https://nanosoft.mn/images/content/File/xogulorule.pdfIn PDF document text
    • http://hzbmsj.net/images/upload/File/bitapodu.pdfIn PDF document text
    • https://cissud.eu/uploads/ck_editor/files/dedodagurilerusoninevovub.pdfIn PDF document text
    • https://akemi.ro/hirek/file/vovadunabaluxoxuluwijomu.pdfIn PDF document text
    • http://legendtec-eg.com/wp-content/plugins/super-forms/uploads/php/files/t9bk3dhom79msv07kqgphmgrj0/duminewu.pdfIn PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/59683368969.pdfIn PDF document text
    • http://studiocastigli.eu/userfiles/files/zirejejatizatu.pdfIn PDF document text
    • http://coatsofarms.com.au/ckfinder/userfiles/files/kipozazejas.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=mitel+phone+manual+ip480gPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F2 18660 bytes
SHA-256: 9ca63cde9f83a49337734e8cb83c1bf3d7bb109e2b0a3fdc2fa62a682a6198af
font_01_sfnt_off00012328.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12328 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1