Malicious PDF — malware analysis report

Static analysis result for SHA-256 2efa83beb898e040…

MALICIOUS

PDF

148.8 KB Created: 2021-08-12 18:25:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-16
MD5: 49d9489a7866c93b5b11384984f4f43c SHA-1: de4c9898e4dd28014bd826055c2db247901addd2 SHA-256: 2efa83beb898e04032e301c730cedc104f58f4a8447186faeea1f6f74058b790
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The ML classifier and heuristics indicate this PDF is malicious, functioning as a link farm. It contains numerous links pointing to compromised WordPress sites and disposable domains, likely intended to redirect users to malicious content or for SEO spam. The document body is unreadable binary data, offering no direct clues to its purpose beyond its structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://banhangcongnghe.com/upload/FCK/file/6765460378.pdf In PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/vlmdsupkqvigm4t873i69ob5c0/bunizasutugimuli.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/144786e378c3b1273bbb255b36f4ef22/67163221621.pdfIn PDF document text
    • http://ebsenglish.net/_UploadFile/Images/file/29929378000.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/6itu8hhuqms9ops69aou0bmq91/98180698748.pdfIn PDF document text
    • https://www.tvmreza.tv/ckfinder/userfiles/files/xozurame.pdfIn PDF document text
    • http://aromamahabaleshwar.com/ckfinder/userfiles/files/63517918653.pdfIn PDF document text
    • http://e-district.org/userfiles/file/70414479481.pdfIn PDF document text
    • http://hopkinshigh1966.com/clients/1/10/1054c114374c88b4a165e91103565d41/File/dedup.pdfIn PDF document text
    • http://lagostena.it/userfiles/files/2673570888.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/numomafek.pdfIn PDF document text
    • http://dzstock.com/Upfiles/file/levoriduzuf.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1d09ae8b11---fanab.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/9130cf4934e9185ab8880d22f3b49947/bidajoxav.pdfIn PDF document text
    • https://learningsolution.ca/userfiles/files/17848509642.pdfIn PDF document text
    • http://airlineclassof66reunion.com/clients/c/cb/cb51827d251551eca15067b3b23580a4/File/pisuxupukepikazovos.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/e2ddd85c4dfbbecc909eb65f96b1dd81/64119704447.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16104f33aa1187---82261305297.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/niwuwuxove.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160764d8f21c0c---gavawe.pdfIn PDF document text
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16084062e9fedc---winuzojebo.pdfIn PDF document text
    • http://mega-treid.com/userfiles/files/jiroletilamo.pdfIn PDF document text
    • https://www.rekalibracija.com/wp-content/plugins/super-forms/uploads/php/files/7d42eb5d066ef63554c9ecfe1de708d2/wipajexed.pdfIn PDF document text
    • https://bataretak.com/img/files/file/jamoxixab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=amazon.com+help+kindle+e-reader+software+updatesPDF 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_off0001e24b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E24B 11304 bytes
SHA-256: 9667e0aad47ba79e464ed89d63da2614fdc6e9c86445f9d02e595dfcf0f370af
font_01_sfnt_off0001fcd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1FCD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000214eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x214EB 18180 bytes
SHA-256: 963d3d66c4ffb2fb27ad0c5f7e8a77a681200b908a51ff0bc0ae114e46e9ca73