Malicious PDF — malware analysis report

Static analysis result for SHA-256 d7a5b63118ad77b6…

MALICIOUS

PDF

73.1 KB Created: 2021-09-03 22:54:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5c63ff62750acdf0a414b2bd1b193811 SHA-1: f10e3d5121f4b8de26e15ce8d98b42450b8dd1e8 SHA-256: d7a5b63118ad77b6614e8c7dfac7f9026049b6b1809dd1b40f02d892ba67a9b8
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file that contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of embedded URLs suggests an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://smidgel.ru/uplcv?utm_term=seven+times+tables+worksheet PDF link annotation
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/1232d4e6d856ae74628fdc3473177153/11904097523.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/3e4dee7d7969cd6c1d81c155b3bd6695/14549680091.pdfIn PDF document text
    • https://roomart.uz/ckfinder/userfiles/files/todijuzekaluzoxigisudo.pdfIn PDF document text
    • https://mfdesign.hu/files/file/1930276960.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/e97a26e5d3d33b4a3099a7245b69f1f6/84084116685.pdfIn PDF document text
    • https://xn----8sbcehyodmtf1czh.xn--p1ai/userfiles/file/71125025225.pdfIn PDF document text
    • http://aci-immobilier-douai.fr/userfiles/files/54013142434.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/in0buqg2ng3gt514qbh620aqas/zujuzarevarot.pdfIn PDF document text
    • https://infotechsystemsonline.com/ital/www/img/file/43154924408.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/a6r5fosvjmpd34trirqrrtm8v6/14489751395.pdfIn PDF document text
    • http://zuche0551.com/upload/file/81456102241.pdfIn PDF document text
    • http://gdbchurch.com/clients/43262/File/feruduzotetusez.pdfIn PDF document text
    • http://garystrike.com/clients/3/30/301ae0ed988f9237e4cb8f8c41f6cb36/File/pidubapu.pdfIn PDF document text
    • https://noihoithanhtuan.com/media/ftp/file/2213445674.pdfIn PDF document text
    • http://praguynakorn.com/praguynakorn/picture/datapro/files/supojufutogezarokizowa.pdfIn PDF document text
    • https://simplehome.ro/ckfinder/userfiles/files/17727113911.pdfIn PDF document text
    • http://doubletroubels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d31105d96a---91634124949.pdfIn PDF document text
    • https://edmaker.site/wp-content/plugins/super-forms/uploads/php/files/b67ccdc01a938027b03462b63fe6848e/60816405691.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c7a6b6a5959---videdobebujowide.pdfIn PDF document text
    • http://nfraccon.org/userfiles/file/lekuvomesinozufiralef.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/a0c2d51650351f038f680d8e2539062a/zikesuraboraj.pdfIn PDF document text
    • http://bienbao.net/uploads/files/76714299409.pdfIn PDF document text
    • https://medsplus.us/admin/images/file/makobulalawesimid.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_off0000bb75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB75 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d38c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD38C 10832 bytes
SHA-256: 4543bad85a212bb646d729f503f912368b43723be3ed3d8962504bc02572ffd6
font_02_sfnt_off0000ec65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC65 16316 bytes
SHA-256: d2ae4e2f884bf345ee84194e34caf58e757222b3fe5fb7df22ff7e9031ec6097