Malicious PDF — malware analysis report

Static analysis result for SHA-256 f88e643e16331d04…

MALICIOUS

PDF

72.6 KB Created: 2021-09-05 19:52:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 751ee38ee48921f9feaadbb170b87e7e SHA-1: 4773d2b33d9bacd0c46c90db237d5f26d26fe8d1 SHA-256: f88e643e16331d04b685e17e8f8447195a9be00c19f1d461e2e3f4220231afe2
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm on disposable hosting. The primary purpose appears to be directing users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://allytemp.ru/uplcv?utm_term=dynasty+warriors+4+hyper+bodyguard+manual PDF link annotation
    • http://gibson100.com/clients/870224/File/nakamoxorikesunet.pdfIn PDF document text
    • http://poorclarescork.ie/images/wasigibazumeb.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/99687072934.pdfIn PDF document text
    • http://extintoresorigen.com/images/editor/xaforarat.pdfIn PDF document text
    • http://liavanhaeringen.nl/userfiles/files/56328380320.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160782bf7037f2---sefirisa.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a78a7d3c89b---10368848090.pdfIn PDF document text
    • http://mixmarketing.vn/upload/fck/file/18381773890.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/xusipinuximimigegok.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/d5c9d9a556463b872dc308ee55e2a9ff/47644359312.pdfIn PDF document text
    • http://maksimetall.ru/files/40920808817.pdfIn PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/64678158930.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9e898d148---72407538669.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/161188f108284e---kaxule.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a34a83a8897---bagapudejed.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/356ef2f3d52778893631cb94114828ae/xutofitinanagirubipulaxo.pdfIn PDF document text
    • https://unitedpetexpress.unitedreloth.com/ckfinder/userfiles/files/57217094221.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/jenidonebebekipifiraxa.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f9361f49792---28181186199.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/konukezopid.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/semimumixilol.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbfee51d83a---26902736595.pdfIn PDF document text
    • 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_off0000b9ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9BA 11360 bytes
SHA-256: aa5b2f3ee93804c6bfb0f17b6665a594b7ece534e62a5a60b67590791d3fc595
font_01_sfnt_off0000d3f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC05 16336 bytes
SHA-256: 7e92f0dc2c1f0af1ee1e3f66ad399256034a85f65b80d06b2daa1723f9acf537