Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8e401a99b36e2c5…

MALICIOUS

PDF

81.1 KB Created: 2021-07-05 05:18:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a5c606339bf9d8938aedb8046dbb24bf SHA-1: ca172fb0a322fe45cbf64def8b6d0321dda6a6eb SHA-256: c8e401a99b36e2c5d92e34de143b18a41677f47f3b27e05972646bd6bfb54a23
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous disposable domains and compromised CMS upload storage, indicating a malicious intent to redirect users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a phishing or malware distribution lure. The presence of multiple external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c0bcc3cf50f---238057978.pdf In PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce7b44b123---zerolutenos.pdfIn PDF document text
    • http://flirdining.com/uploads/files/72514541236.pdfIn PDF document text
    • http://beiwendq.com/userfiles/file/39742229611.pdfIn PDF document text
    • https://festival.bg/fckeditorfiles/file/gogifopo.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bf42cf56bd7---girugonabamitut.pdfIn PDF document text
    • http://artospace.com/pics/file/jelevumanedafagigoxozizuj.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/8a21ef40d9e9e7b54824c6caf281063d/tedewubav.pdfIn PDF document text
    • https://wotfiles.com/ckfinder/userfiles/files/48781458606.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/d2eeb3bfa8d36073d57d7cb010bc185d/57588646033.pdfIn PDF document text
    • http://vamaconsulting.sk/userfiles/file/71385946577.pdfIn PDF document text
    • http://innotack.com/userfiles/files/pebuwetupavi.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/mi02l7s2i9d8os7l6lhm89u5s7/28543701058.pdfIn PDF document text
    • http://badaranquehablar.com/userfiles/files/sudaxo.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/329d20db46bb8bf288774b95f9a2e22e/98321155337.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210701050758.pdfIn PDF document text
    • https://ivanamihic.com//files/bimotexaxenimatuma.pdfIn PDF document text
    • http://www.reenactmentmarket.eu/images/wyswig_images/file/tiwalodutemafopomosop.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210621_154231.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/90949544d64ded9fed93d10c4ccc281b/79122945201.pdfIn PDF document text
    • https://markeishahall.com/wp-content/plugins/super-forms/uploads/php/files/db22b8812b9c26f170d968d74f58af67/jakageser.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160857c811e6e5---buxunujafexanakole.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/160844bbcacd0c---50075848437.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=hop+and+grindPDF 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_off0000db8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB8E 17496 bytes
SHA-256: e919aa8edde2ee77ce96901e4b549359f628a70d3c2dfa25958d9ec443afd52e
font_01_sfnt_off0001092e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1092E 10112 bytes
SHA-256: 0073a043457ca4982213324333f8b8c26ac2926879f7311a8e4eca3aef680668
font_02_sfnt_off00011f7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F7A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1