Malicious PDF — malware analysis report

Static analysis result for SHA-256 803259edd959cd90…

MALICIOUS

PDF

80.4 KB Created: 2021-09-16 15:45:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 574e75edffbf02fdbdf6501f678bc1f4 SHA-1: c9ceedd9a9bb0d527c4734dc0af96f2c9b0aeafa SHA-256: 803259edd959cd909516d566a043dd910afbc255add43aa8dfbadd609adc1f09
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_URI and EMBEDDED_URL heuristics indicates the document's intent to leverage external web content. While no scripts were explicitly extracted, the nature of the URLs and the 'link farm' heuristics strongly suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7068

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://www.derbysignandgraphics.com/uploads/file/felunevegesubuwos.pdf In PDF document text
    • http://arkystudio.eu/userfiles/files/wovifolaroj.pdfIn PDF document text
    • http://suamanhinhlcd.net/userfiles/file/71250721333.pdfIn PDF document text
    • https://vargyasnekonyveles.hu/kepek/other/file/sekusagosenunuwadoj.pdfIn PDF document text
    • https://heureka-cz.eu/files/99049231612.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e9a94d9e6f---4627545873.pdfIn PDF document text
    • https://immsac.pe/sgi_userfiles/userfiles/files/12492761189.pdfIn PDF document text
    • http://www.instalacionescueto.com/nueva/ckfinder/userfiles/files/nifuneku.pdfIn PDF document text
    • http://e2ingenieros.com/ckfinder/userfiles/files/71386713807.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/biwumi.pdfIn PDF document text
    • http://irfanmakina.com/depo/sayfaresim/file/2841336374.pdfIn PDF document text
    • https://cubic.is/userfiles/file/92732077262.pdfIn PDF document text
    • http://studioprogettoarchitettura.eu/userfiles/files/jugutemojemijag.pdfIn PDF document text
    • https://seas2010.cienciaevida.pt/site/upload/file/63825512173.pdfIn PDF document text
    • http://totoumi.jp/upload/file/sexira.pdfIn PDF document text
    • https://hamzakocakoglu.com/userfiles/file/nufiguziwu.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/0de728674bd863fba2be633491b7e6e2/16094775689.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/h54sl36gatp92pt2b0lci5bm9n/30385027062.pdfIn PDF document text
    • http://zapatosperezcabrera.com/ckfinder/userfiles/files/96791946072.pdfIn PDF document text
    • http://efuturesthai.com/uploads/files/biwalogigurumijine.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/11770531742.pdfIn PDF document text
    • https://penzion-pod-rozhlednou.cz/img/file/31286975530.pdfIn PDF document text
    • http://vdtonline.vn/static/uploads/editor/files/rekuropavotudimuwedexe.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/161333a4413d7c---lapodakeviziruwatuked.pdfIn PDF document text
    • https://ifbscalidad.eus/files/galeria/files/72309272949.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=will+factory+reset+get+rid+of+malwarePDF 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_off0000df10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF10 10908 bytes
SHA-256: 71fb98a4dea7e239738ca8dc96898e6b26c0930e0090c2f7b73b5954a4b7741e
font_01_sfnt_off0000f838.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF838 17788 bytes
SHA-256: 4260d4587c83636ffe2ad0ab4c880ac8e3729c40841a26de5e40b6fb1c52e932
font_02_sfnt_off00012683.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12683 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1