Malicious PDF — malware analysis report

Static analysis result for SHA-256 c11fc0e66fe4d4a9…

MALICIOUS

PDF

88.8 KB Created: 2021-08-29 06:58:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 276b8263986883bd91868352d0ca120b SHA-1: d92b0f62d945bc3cbdc0929140c80e9a1617e350 SHA-256: c11fc0e66fe4d4a967abceb66b6490a807c1579765089dc197d5e11f360be533
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm or distribution mechanism. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • 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.
  • 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://cityclick.it/userfiles/files/75936736012.pdf In PDF document text
    • http://cjmfgxfollow.morefriendship.com/upload/files/60577583579.pdfIn PDF document text
    • http://brcassociati.com/userfiles/files/nibara.pdfIn PDF document text
    • http://cascinamana.it/userfiles/file/pulufatufez.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/jozamutopixalizutu.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608540047d3d4---54672934924.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/lobuvewalejon.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/f2adc22c32169d399ff1ee38f5a80834/47193776684.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a668bd89f30---72806565550.pdfIn PDF document text
    • http://soskuwait.com/outscapes/admin/ckeditor/uploads/ck/files/zavojeridifokemumeje.pdfIn PDF document text
    • https://apronorte.org.br/ckfinder/userfiles/files/muzekedadum.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610d5525e9a6a---bovovogoliko.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d62ab47eb81---61231079760.pdfIn PDF document text
    • http://efrex.cz/files/file/25654903358.pdfIn PDF document text
    • http://nifaelectronics.com/userfiles/file/fexodolewuxut.pdfIn PDF document text
    • https://anhhuynoithat.com/asset/files/makodit.pdfIn PDF document text
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/bkljuv2b2bloc3l9tjt5htrac1/jafojudulefevefunov.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608fed334b968---85616452308.pdfIn PDF document text
    • http://jiab.net/userData/board/file/5642414129.pdfIn PDF document text
    • http://jpind.pl/userfiles/file/27442139402.pdfIn PDF document text
    • http://maroba-zirndorf.de/file/96270723988.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/50639223770.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160d99bb45970e---17342981640.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=manual+of+fumigation+for+insect+control+pdfPDF link annotation
    • 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_off0000f6fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6FC 17444 bytes
SHA-256: a1d15a09aed64e0daa3b0836f585b392132f633cec5fd1cdc3b548aceccfd1dc
font_01_sfnt_off00012347.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12347 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013b5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B5E 11056 bytes
SHA-256: a991a7e7c09185ca6407d9901004907d5628ee958ea35778b2a7ba93fcc1e011