Malicious PDF — malware analysis report

Static analysis result for SHA-256 503a0856c2b2e740…

MALICIOUS

PDF

72.9 KB Created: 2021-09-07 03:20:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81251cb247ac0c7a3bed09c2fb23e4ee SHA-1: cb401f2f70c3ffdb2bc359cb22fe4e8707e2b408 SHA-256: 503a0856c2b2e740e122fca01a3f861b18521f3bc65e42f35039b01923b68d87
96 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to various websites, many of which appear to be compromised WordPress installations. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting and UTM term redirectors, suggesting an attempt to manipulate search engine rankings or distribute malicious content. The ML classifier also flagged this PDF as malicious with high confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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 https://aduanaldelvalle.com/userfiles/file/sufateputesilixixo.pdf
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/3ad353ce23a7acef24a05ba38724c3b8/57872887759.pdf
    • http://www.trafikyaren.com/wp-content/plugins/super-forms/uploads/php/files/2at88l0rcg0p305p7o3vm64ug0/dosevisi.pdf
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/e68d4ca007174d803b9f452f297a59df/rumemelolorakazixure.pdf
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/79d80fbb8b6f8a0b3e438e7ca1465553/gujigenovotevotibolez.pdf
    • https://turismopontevedra.com/ckfinder/userfiles/files/1004974244.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612e2dffaffe7---tizawelemaketevaz.pdf
    • https://silky.ae/images/bulk_images/files/22913860832.pdf
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/t16sjpurgl72baav8c0e9l5odp/80546135772.pdf
    • http://mmprogetti.it/userfiles/files/59410348303.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca0453c3cc---zotifimolifoje.pdf
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/50888264955.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/bfecbfc127e1402baf0bff4747fdefcf/28916329494.pdf
    • https://bladmedyczny24.pl/wp-content/plugins/super-forms/uploads/php/files/d4a758f249e5676d59f401451fac2ea7/3989847821.pdf
    • http://kenshopvn.com/uploads/files/dizevanogobowefumaline.pdf
    • http://tsradviseurs.nl/mailing/images/photo/file/11290773613.pdf
    • http://all-pass.com/folder/editor/file/lusipivem.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d13531d50a---72191007430.pdf
    • http://s-moonlight.com/CKEdit/upload/files/potutipobonuvofagexumelir.pdf
    • http://vvk-wiedermann.at/userfiles/file/7172547974.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/746e9e5237ee79c0b186774d0d4bb70b/6033285422.pdf
    • http://atenngo.com/admin/sites/site/documents/11380915359.pdf
    • https://interstudy.net/userfiles/file/58327634332.pdf
    • https://b2b-intelligence.it/uploads/file/64087390422.pdf
    • http://www.hangmandigital.com/files/file/zanipuzitiliro.pdf
    • http://vimar.ua/userfiles/files/74453634329.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=subject+matter+of+public+finance+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_off0000bd19.bin
771912b5ca04dd0e6899481afe829f75dc1fc1a021de3796b7855374d38ddf53
pdf-font-stream PDF embedded font (sfnt) at offset 0xBD19 11056 bytes
font_01_sfnt_off0000d694.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD694 16792 bytes
font_02_sfnt_off0000eea6.bin
aa71a29221b5f1b34230a7bb1c33a7944f5d3725f8538cd44946ace85660d31b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA6 15540 bytes