Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8fb802732eaf30a…

MALICIOUS

PDF

102.3 KB Created: 2021-09-06 12:20:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cf94f893df5876e390e69fab9f7eaa12 SHA-1: 7edfd9ea015fe3ac096d9142c502af5799967599 SHA-256: f8fb802732eaf30a48a71121cd37efa51830687b51d4cf1fe9d43df6fc85eaeb
96 Risk Score

Malware Insights

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

The PDF contains a large number of external URIs, many of which point to compromised WordPress sites or disposable domains, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL distribution suggest the primary purpose is to redirect users to potentially malicious or SEO-manipulated content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://laborke.ru/uplcv?utm_term=atomistique+liaison+chimique+cours+exercices+corrig%C3%A9s+pdf
    • http://kassa.pl/userfiles/file/taferevivu.pdf
    • https://aawyx.com/sites/default/imageuser/file/vuxuguzit.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b56e38627be---76996292021.pdf
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/jnm8tnbj0t7nmbv0lee1320im5/75192669873.pdf
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133716862d40---kulateludivifa.pdf
    • http://jtipartner.com/ckfinder/userfiles/files/zuxuzewakipufosive.pdf
    • http://antonio-pelella.eu/userfiles/files/80160210783.pdf
    • http://maihome.hu/admin1/file/46708062548.pdf
    • https://artenika.pl/fck/file/dexuvepesazolibeligujelil.pdf
    • http://gtlitalia.com/userfiles/files/safujer.pdf
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/r36hu46g1e97t641bsoam5322l/6780408941.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/bd6c9ba499470cde3af554488e4dc9a6/79229724984.pdf
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609403bbb8a5f---44723963851.pdf
    • https://khambenhxahoi115.com/images/files/77309008220.pdf
    • https://ximatinhdongnai.com/app/webroot/files/images/pages/files/92287163887.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161163c614de51---ratisakopomemoxajepepe.pdf
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16113f03bc01cf---64420430164.pdf
    • http://w-f-l.de/user_img/file/jivokagek.pdf
    • http://tavio.su/files/file/jezimetafaxirexob.pdf
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/bc11c6570a7bfce2a3092ac2d4cca608/budirudutanin.pdf
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/51614659738.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16123b40c0e008---94014090330.pdf
    • http://vytvarnyobchod.cz/UserFiles/File/wabozukoxosokobokuge.pdf
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/9b5e64f02d030b35fc5482a73eda7073/juzigoganisitewer.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_off00011e3c.bin
e210ded50e4653dd4e78f1477389e7e8ae6f777b0974454551e8e84d76a6a50f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E3C 11548 bytes
font_01_sfnt_off000138a7.bin
7ca3413cafd0120775396eb377cd70fda58b90dbfd32f89e2df5397590317071
pdf-font-stream PDF embedded font (sfnt) at offset 0x138A7 21712 bytes
font_02_sfnt_off00017012.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x17012 16792 bytes