Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f8c20b454c5d7fa…

MALICIOUS

PDF

76.2 KB Created: 2021-09-01 08:43:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1e49045711807d5840f0299278bbe246 SHA-1: 13d4d5544ae9426af293840df176c685d22dcd9a SHA-256: 9f8c20b454c5d7fa52483010eb4fae88f06ccfa1d19d48dccd271f85caa7690c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8636

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 https://krisoc.ru/uplcv?utm_term=quintal+into+kg PDF link annotation
    • http://alphasigmaoverseas.com/userfiles/file/wegurodoge.pdfIn PDF document text
    • http://clarksville.net/wysiwygfiles/file/15721631039.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/mukuvulimekukofesapudaze.pdfIn PDF document text
    • http://rotarybrescello.it/userfiles/files/14249408063.pdfIn PDF document text
    • http://paddockj.com/user_data/editor/ckfinder/core/connector/php/upload/files/88167761438.pdfIn PDF document text
    • http://alliance-vietnam.com/upload/files/bokogevurapixafalibivevo.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/67591054689.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/160863a4210ac5---simasagexerizunefe.pdfIn PDF document text
    • http://abpaluso.com/upload/file/jijifinuzisexiponere.pdfIn PDF document text
    • http://wasserburg.pl/userfiles/file/95565872924.pdfIn PDF document text
    • http://market-oborudovanie.ru/upload/file/89034983339.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/7k8d5nhok359a73p9i7o425p0j/nosuxiburadorumemit.pdfIn PDF document text
    • https://clifestyle.net/uploades/userfiles/file/lujuwere.pdfIn PDF document text
    • https://melz-feu.ru/upload/25790284261.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb11c4edab---76517943766.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081f45bc74a4---14623248817.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/dnnojsohifb9i6ehg2j9uiq522/72978935971.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/949ce270f183d4afe8465308e70a5788/gafixowovoxudano.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/9mffjgvm6ajq1io6l7e87m90n4/18711999579.pdfIn PDF document text
    • https://gizaviation.com/uploads/files/45782448795.pdfIn PDF document text
    • http://ukonlinedirect.com/userfiles/files/wibonowajokuvasuseribidon.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a1135271c6d---tinemajuxokufejuwok.pdfIn PDF document text
    • http://remont-elektro.eu/archiv/file/wabired.pdfIn 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_off0000d0f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0F1 10136 bytes
SHA-256: dcfc2d704bb3b6a54c050a1d95c1a436053e2ef0773a95a99a741add00a2e092
font_01_sfnt_off0000e7bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7BD 17936 bytes
SHA-256: f4a5c9b0d551c94363fc75bf3c593b49c4be1cfbf07cf95d57ae63a7cb199f83
font_02_sfnt_off000116aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1