Malicious PDF — malware analysis report

Static analysis result for SHA-256 16b771bc543a8b2b…

MALICIOUS

PDF

93.5 KB Created: 2021-08-12 15:19:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 1ee76dd50cacaa5b03e900999444ab8b SHA-1: d5a5fbe8b1e4c63c043b57693a834dc8593f489d SHA-256: 16b771bc543a8b2b726252582c5c31fa07e19880d305e736aace32e16cd4265d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links pointing to compromised WordPress sites, indicating a link farm likely used for SEO poisoning or to distribute malicious content. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the nature of the link farm suggests an intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/dda845c00194ad6be2e9f51fd116a3c3/nukaf.pdf In PDF document text
    • http://droneducational.com/admin/userfiles/file/podaxa.pdfIn PDF document text
    • https://stegopackaging.com/wp-content/plugins/super-forms/uploads/php/files/r8sgv0ie6hopi31rr22ct59fbu/56788389975.pdfIn PDF document text
    • http://carneslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/96215975473.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/kibesidafurororezil.pdfIn PDF document text
    • http://branonperformance.com/ckfinder/userfiles/files/58614426455.pdfIn PDF document text
    • http://noithatmfc.com/media/ftp/file/betuvuponufuwesane.pdfIn PDF document text
    • http://ansonseatery.com/uploads/files/xinomijumakexozatanotuxu.pdfIn PDF document text
    • http://turatabor.hu/media/xiduzetevodog.pdfIn PDF document text
    • http://philippinesroadshow.com/wp-content/plugins/super-forms/uploads/php/files/6b549df2cb055344ae2e2514e6a636c1/kurawejalanokid.pdfIn PDF document text
    • https://sonarmusic.hu/up_image/file/22076875950.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/16517861365.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/9phh4fjvg1qviub9l2o5o7hn9m/zononidexumofujot.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1627457062.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/16098113e05802---78786846293.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608674089bbd9---gajaxa.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfe6745911---zekako.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/k76qs5govg4r01rlidcgvs3h66/50955352266.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/0c8b734ae320befc95a11e7ca1328dee/baxepaguruwojomiruxas.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/50152389977.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/bd6264e64ccfd1a366f08bd70a059b68/kudizemafijagavugif.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/bbab2cec4a91bf7a6046490dcc55e2e6/39125637851.pdfIn PDF document text
    • http://gat-asset.com/CKEdit/upload/files/lenonajigopadoves.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/oi3tci41qfhuqek3k1rmrf0bq1/92278138375.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=10.s%C4%B1n%C4%B1f+co%C4%9Frafya+2.d%C3%B6nem+1.yaz%C4%B1l%C4%B1+sorular%C4%B1PDF 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_off0001015f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1015F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011971.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11971 19968 bytes
SHA-256: 7799386dec3311c9080130d33435775c5bbf6a025e9dabb30c1fe9d4d9aab0fa
font_02_sfnt_off000149f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149F0 11476 bytes
SHA-256: b823b95a04413ee5865fc283ba006cd7b08f5226697862f82dad786ab50c99ba