Malicious PDF — malware analysis report

Static analysis result for SHA-256 81f1dda973ba40c0…

MALICIOUS

PDF

85.6 KB Created: 2021-06-26 03:02:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: e3d261ab66bf963f24d8682866ea56ca SHA-1: 112c06ced84eb3c82683fd24bd2096a65a03068b SHA-256: 81f1dda973ba40c0f416ee7618e477c805abbb22bb0819257ed587abd8d78667
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs that form a link farm, with many pointing to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the structure and URL patterns are consistent with phishing or malware delivery campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • 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://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071568d19561---lexeso.pdf In PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/p4d18iblv15t81905sng27edfe/pegefasatomuf.pdfIn PDF document text
    • http://asupuro.com/user_data/image//file/96770538187.pdfIn PDF document text
    • http://iglozawiercie.pl/zdjecia/file/paremevaperado.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cec40ea5227---98586341429.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/79526559199.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/31m0l4sedfkm70afgdjkb9bgfm/18322792918.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a10a882404a---48342675984.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/ohgn94sarlc5l1plbcma0jolso/28338412455.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/97dde65435a0c4c93df48cd81218f778/befarizorulotigejupo.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1608ae5837edc2---zuperavigerapabutugo.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/opf0akpsm86ln25lfecrue4mf0/zetusuloledazoduso.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/bulisuviwobemamewifat.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/39221688947.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/sajunelejekigukalifupig.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/nutisuriresewetejefam.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160aa116ff3bcf---womonulotuvepusujenazunow.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095bce225957---17772387557.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/ehl9s4otqm6pgumesqs9t1atn6/21059210859.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2700aeb3e3---10420307284.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/tenupezuxakodiwukul.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/b503a77bb096ba93bce6c2a6bab4f691/rezukisaribewosesin.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608d4882b7f29---29663878251.pdfIn PDF document text
    • http://topas.lt/userfiles/file/66088854845.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=tom+misch+disco+yes+bass+tabPDF link annotation
    • http://s292376414.onlinehome.fr/datas/imgmail/file/78928004530.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_off0000e9e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000101f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F8 10600 bytes
SHA-256: b2d10a67e144741d8f17998b72972ceaa6d12549f24ab80e22352be1a7bbee58
font_02_sfnt_off00011a42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A42 17064 bytes
SHA-256: 52c09d1fe601ac4c5214c44bf7d1bd8d5faac6398523e8d573e58f04d4094d3e