Malicious PDF — malware analysis report

Static analysis result for SHA-256 77bdc459bc7a469e…

MALICIOUS

PDF

88.6 KB Created: 2021-09-01 01:01:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ec85ab1db9e1e2106610603d754ea248 SHA-1: c21b8535108ffa59ddf16bfbf0312946ba27f0f9 SHA-256: 77bdc459bc7a469eca2b67904d36c3d949c85601b3c129d6b0bce91987f0fa84
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by multiple heuristics as a malicious PDF, including a critical ClamAV detection and a high ML score. It contains numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and embedded URIs strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://synerhu.ru/uplcv?utm_term=how+to+make+rarawr+in+monster+legends
    • https://suavitinhtannha.net/upload/files/bofoj.pdf
    • http://njuhome.pl/ckfinder/userfiles/files/64925874780.pdf
    • http://www.agenbenangbandung.net/file/dawaforudojonerakufod.pdf
    • https://praward.tw/wp-content/plugins/super-forms/uploads/php/files/b7e6fd3304931c5cf7126125d9982b27/90363941685.pdf
    • https://bodzlomu.com/userfiles/file/koguvitude.pdf
    • http://grgct.com/ckfinder/userfiles/files/buburegobimawawag.pdf
    • http://big-blue-bus.com/pics/fotos/1/file/40322889499.pdf
    • http://mrpokedb.com/uploads/files/rapiwojererum.pdf
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/02f1497259298dc969e2bbb48fe84c04/bemaloxaxuxesuwu.pdf
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/torazetuw.pdf
    • https://motelandratecuci.ro/userfiles/file/11237229204.pdf
    • https://peterdegendt.be/file/gerisisoxisevekefeve.pdf
    • http://ankurgroups.com/userfiles/file/vapenurigagorune.pdf
    • https://www.nexidia.it/wp-content/plugins/super-forms/uploads/php/files/19ad7d3c4e35809237ccd58b61d1b9b3/77015680125.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/33316bd51c6ee2a495200cdd78be4ee4/dexesanulosesirusepu.pdf
    • http://cbgnfinance.com/userfiles/file/mojibilesam.pdf
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bb930991b6e---xafebidapepaxiwemazeze.pdf
    • http://machulski.com/public/file/98284616097.pdf
    • https://karlschool.org/uploads/files/202108232053062573.pdf
    • http://www.atccs3.it/atccs3/fckeditor/editor/ckfinder/userfiles/files/16527794559.pdf
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed15d54160---furazabu.pdf
    • http://synthecinter.com/userfiles/files/pukojokunewit.pdf
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6165e3665e---80660165966.pdf
    • 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_off0000f1d4.bin
43f9b27e97208ad36d1d7c7a6e8bdeccaf07c1eb475e00a5693ec7e27debe392
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D4 10760 bytes
font_01_sfnt_off00010a53.bin
c55c24c205c508c53b8f88a2830fc67761c6964989df54d8d30da9acc6490f06
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A53 18800 bytes
font_02_sfnt_off00013b53.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13B53 16792 bytes