Malicious PDF — malware analysis report

Static analysis result for SHA-256 9421928d061df3c7…

MALICIOUS

PDF

134.1 KB Created: 2021-07-01 15:07:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b7f82311792a083e5b22c9b9ba321965 SHA-1: 27724a6b12059f2646dd441bf1c2c55bd1b25137 SHA-256: 9421928d061df3c7b79fd0433c68fe557664cb768ade83c79935db7b24cd2b8d
96 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to redirect users to potentially harmful content. No scripts were extracted, but the primary attack pattern involves luring users through malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9639

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://krisoc.ru/uplcv?utm_term=standing+besides+or+beside PDF link annotation
    • http://ohsclassof73.com/clients/9/9a/9a21b0b253f7c4eafe662346d237c286/File/tefevavibepejoramo.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ca4174b4f21---wifujesexa.pdfIn PDF document text
    • http://mkngsp.ru/upload/files/26356835678.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160c8ecd79839a---73374276538.pdfIn PDF document text
    • http://kripasec.com/userfiles/file/42887181018.pdfIn PDF document text
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/dc1e6b4f473ddcc2b6231e4bb6651916/13937806775.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/459c7a89a54f1fe6114022bf288cdc90/zasokuxikovip.pdfIn PDF document text
    • http://goref.ru/files/file/87999668138.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/162907a964a1f9cf4a8883c777fca2f8/11184770948.pdfIn PDF document text
    • https://vannordenvastgoed.nl/userfiles/file/sipisugi.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609214faa9b36---lotolivefexabupejifegavu.pdfIn PDF document text
    • http://baugeraeteverleih.de/benutzerdateien/gozegizajudomekeladulevi.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f7371441bd---vowexenejevu.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/1v9smp2c6tch70874vll2t1gn1/notixofesizavoj.pdfIn PDF document text
    • http://choinka4x4.org/cms/files/file/monimugi.pdfIn PDF document text
    • http://elsekmont.eu/userfiles/file/vubud.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/0613df6c6bfc9c8307b6d64a8982b1fb/53749194568.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/tq4807amtihupve4lps5t7uhmi/92505516154.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1606ced8f04e3a---58253547226.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/5sddic55anuqhet2tkk0k2u3h2/tamamofuturolanezawafap.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160b627a50f3b2---78393178058.pdfIn PDF document text
    • http://jrmhandling.nl/upload/file/terulizi.pdfIn PDF document text
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/1afeaa153b247433b8a1f566ebe28159/meruxijusomekul.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/3787895b1c5caf7a8a240b4d8b30a99a/lukuruzela.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608312ea1b0bb---talabilosukelote.pdfIn PDF document text
    • 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_off0001a9d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A9D2 18272 bytes
SHA-256: c8978d2d65b36b2d32a49b38fcbb1edb69ef48377fef7a3c5683d6c7b5fd8b53
font_01_sfnt_off0001d920.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D920 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001f137.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F137 10592 bytes
SHA-256: 5588417be922f60c65338e0c962e49bd07fa82112425f2f0738649cd997b5843