Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b833f6dd1552e66…

MALICIOUS

PDF

72.6 KB Created: 2021-09-29 09:47:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 02244ef9120e2adf5f8f7f58a7a07e49 SHA-1: 75c26f11360f06dd62df4f748de76863be5dd6e0 SHA-256: 8b833f6dd1552e6617bd59b5434cbdb1022ba49a060900270e274c5743103fc6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing. The embedded JavaScript likely facilitates the redirection to these malicious sites, contributing to the overall attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d045f25cd8---38292366169.pdf In PDF document text
    • http://esistore.be/userfiles/file/72423820070.pdfIn PDF document text
    • http://music-saikung.com/ckfinder/userfiles/files/nelimugawemevewaluja.pdfIn PDF document text
    • http://lesmashclub.com/imgUpload/files/jazoxi.pdfIn PDF document text
    • https://najlepsze-w-polsce.pl/uploads/78463745826.pdfIn PDF document text
    • https://ahirealty.in/admin/userfiles/files/bowoxamezupos.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/jugaritoxolowobex.pdfIn PDF document text
    • http://solentpodiatry.com/jackvl940/web/content/images_uploaded/file/kunikuxopune.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/161467b329dd0c---fadakub.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/79385180738.pdfIn PDF document text
    • http://italianopizzeria-pg.com/uploads/files/98429913499.pdfIn PDF document text
    • http://yourmoneyyourbank.com/uploads/File/wepusugeteno.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/zavukukez.pdfIn PDF document text
    • http://twfbs.com/ckfinder/userfiles/files/jolamipiwuliw.pdfIn PDF document text
    • http://trivio.it/userfiles/files/bamazeziseruxagolofak.pdfIn PDF document text
    • http://happyland-nsk.net/ckfinder/userfiles/files/jepivomolinanodaxi.pdfIn PDF document text
    • http://chamdure.com/DATA/files/sisumanunagofaso.pdfIn PDF document text
    • http://grubstreet.ca/ckfinder/userfiles/files/52414645101.pdfIn PDF document text
    • http://zeroseistudio.eu/userfiles/files/53683949631.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/60c52ec66972c463798e937bf6e414d8/dewetafafuvonu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=the+mastermind+marketing+system+jay+abraham+pdfPDF link annotation
    • https://mediacentre.heathrow.com/js/ckfinder/userfiles/files/tanoxuduzatenononatute.pdfIn PDF document text
    • 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_off0000b351.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB351 18000 bytes
SHA-256: a5143dcbee2392682dd83c54f050e023c34efd8fb71b394b05e742652429876d
font_01_sfnt_off0000e253.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE253 11220 bytes
SHA-256: 4eba8ce5584500369bec73b5f0052730eeab226d56446703ce0444ab726b383c
font_02_sfnt_off0000fbfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1