Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4cf4ba4d95e66df…

MALICIOUS

PDF

99.4 KB Created: 2021-08-04 19:57:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e02fb14c277854cd3ad7f8756bfeb2af SHA-1: f4f64f2636f6dc45f9c16eb0efcaaaefbf07259b SHA-256: b4cf4ba4d95e66df08ca9adf373c23d53cfb8bf029f05091ba43763c9c2e3d2b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads and disposable hosting, indicative of a link farm used for phishing or malware distribution. The presence of an embedded JavaScript stream further suggests malicious intent, likely to execute further malicious actions or redirect the user. ClamAV detection as Pdf.Phishing.Trojan confirms the malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://myphamlulanjina.com/upload/files/rilemupetulafe.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b693e33e39d---fetek.pdf
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e628908676---kazeravejetapozowegozuk.pdf
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bedd79d82ac---24970037852.pdf
    • https://nstoplana.rs/ckfinder/userfiles/files/91345209840.pdf
    • https://www.agro-zavod.ru/app/webroot/js/ckfinder/userfiles/files/guxidaduxuza.pdf
    • http://staceyasp.com/UserFiles/file/67651482394.pdf
    • http://hairtransplantmangalore.com/uploaded_files/userfiles/files/vavotalezogajuvesa.pdf
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/f4f6sfrlhl86ht994qh2981dii/jidinavuperakezej.pdf
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/15dcf40651487bd4b8bb275fce874fc3/65553373829.pdf
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b50bbf3fda1---30910215191.pdf
    • http://lueckerreunion2020.com/clients/e/eb/eba09433058400eda594a485f9004317/File/kesevonevekeves.pdf
    • http://ahkkpcm.org/userfiles/21251417079.pdf
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/titowaxomidexoximus.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/tjadf18jpc18sr1265ol3j4jj6/16933767482.pdf
    • http://aihyang.com/userfiles/file/jogawotabufuzobigorojer.pdf
    • http://thetsaban3watnuea.com/UserFiles/file/zafevetedudus.pdf
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/f88c82598bdb3ef46201e3794393e952/kekitu.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/7q3k9h8bikhjg2issede8d9nb5/wezukelikimapaxamob.pdf
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f408793ca7e---rufexejekujepiraz.pdf
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097937f6a877---nuwulukewigagow.pdf
    • http://dermalab.pl/userfiles/file/87880875977.pdf
    • https://tort-art.ru/userfiles/file/kawusunadix.pdf
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd8c3da206---57860238332.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=chilobrachys+sp.+blue+vietnam+wikipedia
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010f43.bin
81e95ad7c4f869130feab5ee406d38832a5f5a7095968245f5d015ffd26b6b01
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F43 23844 bytes
font_01_sfnt_off00014c84.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14C84 16792 bytes
font_02_sfnt_off0001649b.bin
cfc8d2f4ea0e7682a428b8f0873e38a241ffbf2e7e523b9e05a1868e1b72e2c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x1649B 11476 bytes