Malicious PDF — malware analysis report

Static analysis result for SHA-256 caf91f1625c6198c…

MALICIOUS

PDF

84.6 KB Created: 2021-06-29 18:51:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6ea866583d5cfd3b9b482ecdd453b945 SHA-1: 079e479bd7f830ec63dc33c1e6f8007ea015aaa4 SHA-256: caf91f1625c6198c7b888979aedbaa408cc4dff28e2fda1b72c1b8db85650ee5
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 links, many pointing to domains associated with compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier strongly indicated maliciousness, and the structure aligns with techniques used to distribute malware or engage in phishing by leveraging numerous external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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=storyboard+interaction+design
    • http://kme-kme.cz/files/file/5450644300.pdf
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9b5944dadc---dokodisajulo.pdf
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2f628c381---karebovigapimuxiw.pdf
    • https://oumkua.com/userfiles/file/42858351767.pdf
    • http://bvsaigonbinhduong.vn/uploads/files/1634096499.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/160adaafeaffa5---lilavasikezowojukemuzagun.pdf
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160906342716b6---26242915465.pdf
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/35mis6de8cr0dd78hfjtujp5f1/vuredumafixerajoseteg.pdf
    • http://podushka.by/files/files/kegijexububudawavufu.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b20ca4e827a---16020159254.pdf
    • http://fondationmonetoile.org/clients/0/0e/0ecfe6182781ff486fe5156d2e85c11d/File/99901918510.pdf
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c18be2ba2b0---28139460543.pdf
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607e625b72a93---vofetipaxiwidiwora.pdf
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/1642308657.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/qe43v0lkvo115g6p0vokaobu0h/2566214307.pdf
    • https://securitydm.rs/slicice/file/9028984746.pdf
    • http://sfera-vlad.ru/img/file/5237788662.pdf
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/5d03fa2c4c09a2791b81e9d19d68fdbb/29242913185.pdf
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/b9aabd1f9060a8a0f16133fe47881f19/fugagedubopiw.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/huv676p05cem1qn3l8mqc86fvn/87627165846.pdf
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/c29d08bb9a50282374efa226e0a7a597/duretikumosonusubekome.pdf
    • http://fenotropil.ru/userfiles/file/vegalufavosotup.pdf
    • http://southport1969.com/clients/861680/File/kokirumibovadefa.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_off0000e869.bin
832a50c3015490c0f167ba2f546526f0aac3d1e3606f10c33302f1cb37c3a6fb
pdf-font-stream PDF embedded font (sfnt) at offset 0xE869 16864 bytes
font_01_sfnt_off00011422.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11422 16792 bytes
font_02_sfnt_off00012c39.bin
7e53eb935a339427285600ee880781900305073b3da91712846a024ab2fe906a
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C39 10828 bytes