Malicious PDF — malware analysis report

Static analysis result for SHA-256 91ff61483bc1af7d…

MALICIOUS

PDF

93.3 KB Created: 2021-09-04 11:13:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 231999452ed79bd754b102e4871e07d2 SHA-1: ba98fe2bda71e1c77b58f5f214297ba2a33f41a4 SHA-256: 91ff61483bc1af7d9b235ec5ec153b2987f42ef0884d7cd664e4788c7710c8f3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. The heuristics indicate a link farm pointing to compromised WordPress uploads and disposable hosting, suggesting an attempt to obscure the final malicious destination. ClamAV detection and ML classification confirm its malicious nature, likely as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/4db275149a33696aaacbbeb3137683e4/54974852571.pdf In PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/776a0458e752d273d58802e64f62bc1a/jerilojixuza.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a0055ee45c3---rebapuwamel.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/bdbd261dbc1bd58abd3a361541df4f71/23304644287.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/c2460bca313dfc2d2062340fff5c0736/pulurazulapizivapukimel.pdfIn PDF document text
    • http://www.specemc.ru/upload/files/mawuxozuvuxulijofugosaxi.pdfIn PDF document text
    • http://tiyuchangdi.com/upload_files/files/20210811_220629.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af9d55eb9db---vodafugosiga.pdfIn PDF document text
    • https://turismo-galicia.es/ckfinder/userfiles/files/gopasipunoganege.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c4a385680f---wedevolibi.pdfIn PDF document text
    • https://www.ideaklinikankara.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d7b277b5fc---gamipanaf.pdfIn PDF document text
    • http://planbmedia.hu/files/wavolofinorelososogugulu.pdfIn PDF document text
    • http://maezawa-jidousha.com/js/upload/files/lisabixuxerakofirakaxox.pdfIn PDF document text
    • http://magyaringatlanadatbazis.hu/dev/_user/file/44875563363.pdfIn PDF document text
    • https://jerseyshorepirates.com/userfiles/files/memata.pdfIn PDF document text
    • http://hani-bee.com/userfiles/files/purepisir.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f58fbcfe58---dewajitutab.pdfIn PDF document text
    • https://opsclown.it/ckfinder/userfiles/files/linowokuwemugiwidewise.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/2d077ee3b76c23ca77b0e380d763ec53/85736821046.pdfIn PDF document text
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078ad36e1768---vibevorizekoxumunixux.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/300841ae6976774f762ffef2b942cba5/tutenufet.pdfIn PDF document text
    • http://dzbnf.com/upload/file///84252957082.pdfIn PDF document text
    • http://litroshaber.net/resimler/files/11832047602.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/3450d977f2abb3f7586a15a48a0dfdae/52942512713.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=precious+heart+romance+pocketbook+pdfPDF 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_off000103b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011bcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BCD 11172 bytes
SHA-256: 40efb6f3eaf39fedf5be953fc55f38c92c9bb43eae242d443b01ec79a441de9c
font_02_sfnt_off00013582.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13582 19224 bytes
SHA-256: b6e732409733b965afe1e5b61e46102ba6ba2c8f705861d9277528385dc529ea