Malicious PDF — malware analysis report

Static analysis result for SHA-256 55df910942ba3102…

MALICIOUS

PDF

82.6 KB Created: 2021-09-02 13:53:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f7c312e3ae1354105f6c0102650d46b4 SHA-1: e9b77a37eb27451883be2381fba5c1f4656a71da SHA-256: 55df910942ba31021579c1c6697d06b6fcd57fa2b6b4f2a89d998e4de3760317
96 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, which are likely used to host malicious files. The ML classifier strongly indicates maliciousness, and the heuristic firings confirm the presence of a link farm on disposable hosting and compromised CMS uploads. This suggests the document is designed to lure users to malicious content, potentially leading to further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://queure.ru/uplcv?utm_term=sandbag+training+course+pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a4566da30d2---84826289817.pdf
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/f46910a60f469486e9d9d71135ea1fa2/64845902970.pdf
    • http://jevades.com/aircraft/fckimages/file/xoduteruxubivojarun.pdf
    • http://jfhcoaching.nl/userfiles/files/28880625357.pdf
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202108/file/letalatu.pdf
    • http://anandtouristcorporation.com/uploads/kofedop.pdf
    • http://inoxbienhoa.com/upload/files/gatenaxa.pdf
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/464512588eedf869f163d14cf3c5ce12/113689490.pdf
    • http://abwmountvernon.com/uploads/files/mamegazomuwege.pdf
    • https://tselectromechanical.com/uploads/CKfiles/files/gaxupevuwewabun.pdf
    • http://surmounttravel.com/userfiles/files/zomepow.pdf
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edefb1b8b43---lazevaxowepiga.pdf
    • http://cathugo.de/res/wysiwyg/file/fuzegukozipumemuma.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/9qh9ipakgssfal7ei7lfqfa184/53065150444.pdf
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/adc8ff2fadf55cfcd89ff0ed63b15de4/juburogajagotudijamaka.pdf
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ebe78070e---mesuzadunaxikofe.pdf
    • http://rspon.pl/images/wyswig_images/file/10580124297.pdf
    • http://mdbim.pl/ubezpiecz/obrazy/file/puxenasepenab.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16105e5c1373bd---gopafawazoxawisodebew.pdf
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096827e99c82---20277193312.pdf
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1608a1806b9810---43094967333.pdf
    • https://accuratesearch.com/userfiles/file/5608949487.pdf
    • http://angel-conference.org/upload_fck/file/2021-8-31/20210831175654758864.pdf
    • http://misosmile.com/upload/editor/files/garotoratujaniguxuv.pdf
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16097229c5154f---latavelotitevifanojogari.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_off0000ddc4.bin
826c9fb30436513d67930bfe37a8c0dbccdf2891c6747875b15120aa6df03cf9
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC4 17444 bytes
font_01_sfnt_off00010a8d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A8D 16792 bytes
font_02_sfnt_off000122a4.bin
f3544629e78a8f3f1b63da09601edb8f16dbbd136f3244433e817d27092e6223
pdf-font-stream PDF embedded font (sfnt) at offset 0x122A4 11064 bytes