Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8ef55aab662a5a3…

MALICIOUS

PDF

88.4 KB Created: 2021-07-19 12:14:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3ac2429489611f9d8feed478288312c6 SHA-1: be33bf2a9186901483f5b4746b362793d372ce95 SHA-256: f8ef55aab662a5a30deb39ae4ee89e89c2fbfcc8fd4e10371b89ce8819c80d71
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous other PDF files, many hosted on compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the presence of multiple links to potentially malicious content suggests an attempt to distribute further malware or engage in SEO-based abuse. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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://aihyang.com/userfiles/file/4513492166.pdf
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/d996f3c0d64f01d50c9e95ef65ba3b46/36770874635.pdf
    • http://elitvorota.ru/f/file/41003332854.pdf
    • http://magyaringatlanadatbazis.hu/dev/_user/file/wafor.pdf
    • http://albertopizzetti.it/userfiles/files/24562509060.pdf
    • http://maihome.hu/admin1/file/xewewulebogutabi.pdf
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/b9956ae9394438097cdc6bd83145a3d1/42723496351.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2c88dc2b9---mewip.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16086303b99d6e---59625939369.pdf
    • https://drlanda.hu/user/file/47628585965.pdf
    • https://m-isc.com/userfiles/file/rexubenobesufusebi.pdf
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9daf32947e---fexejigepiju.pdf
    • https://www.propertyfilevault.com/wp-content/plugins/super-forms/uploads/php/files/860b1e576c3d96ab964504e70ad49e28/64300881234.pdf
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160845415baefe---wupasivavaze.pdf
    • http://artechq8.com/beta/uploads/files/rojufezasanaluporomovin.pdf
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/e30ffd5c24aac9365fd42e7501f9a851/10664805385.pdf
    • http://dok-vo.ru/userfiles/file/jibexexugukojomake.pdf
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/qt5ghnna6nnuhcbkjfalen66o8/powamozexitodo.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/f3ac2065d3c680780e3c4faa4eb7ab21/xidasilosenibit.pdf
    • https://aiwatopup.com/ckfinder/userfiles/files/pugovapimasigidakifo.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c516d32732---zuvogi.pdf
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607506b4d114a---pokisizefodiginetasag.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/160728947de9a3---zusejijevakidikuku.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=event+schedule+empires+and+puzzles
    • https://tes-sys.com/uploads/ckfinder/files/20210713/16261258968047.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_off0000f76a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF76A 16792 bytes
font_01_sfnt_off00010f81.bin
28eaad614c16e4a33824f3bbab7da1eace535547172921625fb04b37f7d2fbf9
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F81 10868 bytes
font_02_sfnt_off00012866.bin
338b0a320c1675d711b63ed22f1a4b60569195c07222d63034d94e23b9056dbe
pdf-font-stream PDF embedded font (sfnt) at offset 0x12866 16756 bytes