Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbceb71d18da6da0…

MALICIOUS

PDF

78.7 KB Created: 2021-09-08 15:08:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: be90e1bd6ca69cdcb37c1b0efb8c2907 SHA-1: 279b992992769736023f4f06c2d9b3c9b8638d0f SHA-256: cbceb71d18da6da0b5a317834130f19c7113ab6780086bd81594cabd2a88894c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS uploads, suggesting a link farm designed to redirect users. The presence of a URL with 'pdf+to+jpg+converter+offline+installer' in its query parameters indicates a lure for potentially unwanted software or phishing content. No scripts were extracted, but the overall structure and URL patterns are consistent with a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6181

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
  • 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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://mikllc.mn/uploads/files/61573595411.pdf In PDF document text
    • http://biometria.pl/photos_fck/file/regebabibomimoxurililuniz.pdfIn PDF document text
    • http://thcsducthang.pgdbactuliem.edu.vn/ckfinder/userfiles/files/batoge.pdfIn PDF document text
    • http://orderbestwings.com/uploads/files/57921437189.pdfIn PDF document text
    • http://ytovietnam.net/ckfinder/userfiles/files/mamuz.pdfIn PDF document text
    • http://giayviettri.com/img-ftec/files/14840441376.pdfIn PDF document text
    • https://ahha.az/userfiles/file/totufesajulunesowisusalo.pdfIn PDF document text
    • http://avsa.org/sites/default/files/images/files/wuzuxugarawilek.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/zesuxoxizugizazigugesowe.pdfIn PDF document text
    • https://indianhairtransplant.com/ckfinder/userfiles/files/relujivemix.pdfIn PDF document text
    • https://xetnghiemadndanang.com/upload/userfiles/files/diruwuvix.pdfIn PDF document text
    • http://boki.hu/editor_up/37448930700.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613761e39179d---45478920594.pdfIn PDF document text
    • https://dp-engineers.com/admin/userfiles/file/nivonarosujefiwikelevevas.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1613815974ba1b---tolepogaku.pdfIn PDF document text
    • https://workinhotel.com/upload/fckfile/68342970868.pdfIn PDF document text
    • https://askisan.com/upload/ckfinder/files/gapezivoz.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/0b90492fde4cae457279c45f71eb0ab7/sibopevun.pdfIn PDF document text
    • http://kubablimel.pl/Image/files/zofitovusotakosugez.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16133c34a9c76f---20413932057.pdfIn PDF document text
    • http://www.ocptecnology.com/admin/uploaded/fck/file/66268911861.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/a497e05fe58dd8164204932adf9001bb/1932456092.pdfIn PDF document text
    • http://ptichile.cl/userfiles/file/69146104435.pdfIn PDF document text
    • http://skrutit-probeg.ru/upload_picture/file/36253721875.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=pdf+to+jpg+converter+offline+installerPDF link annotation
    • 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_off0000d865.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD865 10992 bytes
SHA-256: c939665b19a47929ecb1a0af2468b1b4d8e3ea66e94ca9fe4477da8a63cd41d0
font_01_sfnt_off0000f1d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000109e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109E9 18204 bytes
SHA-256: 8757688df733da8d9e23542ddb89b579b6b4b865c133034d746e13f10d239754