Malicious PDF — malware analysis report

Static analysis result for SHA-256 51f175a5e0a8d1a2…

MALICIOUS

PDF

72.9 KB Created: 2021-05-11 04:44:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: e0c23cb2ed3e564ca04ed18c80ada1d2 SHA-1: da9a14660116cfae5f20077ec2b8a29a13d24e16 SHA-256: 51f175a5e0a8d1a22a93947f240f46789db45ea5e470f91b9a4e96d8ec123b5d
156 Risk Score

Malware Insights

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

The PDF document contains numerous external links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing lures and potential malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://archism.ru/uplcv?utm_term=cardboard+dollhouse+furniture+templates PDF link annotation
    • http://www.ecvbrass.ch/user/web/file/38175761423.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16086764917b0e---wetopij.pdfIn PDF document text
    • https://an-professional.ru/img/files/file/23845470007.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/0kuf6ps1s3n83t598k7g3tec42/8556335416.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed5988883c---41469145795.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/f8f80f30f4685e83e4e43c411c6c886e/nixelorinapetajomiv.pdfIn PDF document text
    • https://arhometutor.com/userfiles/file/56159247395.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094828e6f1f6---sitifosotobagesadiw.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/7088c8ede7b30fcd6e22faff02bf8dd4/fexojisajoxuzed.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/18f5b1cbfb5f9db512e3c4ff613d0797/72038681416.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16071b1156b032---dapumuzerezumadiluvixed.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/b04db253689de81db73d96bebf2ef47e/22573708942.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/160858bf1772d7---junujofajogafut.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/tvo8jbmgpiq23logshtvcgnld1/nomajinotefakupigutovod.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f85debe610---44191495114.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/e2404t3h0kgpkbip29vggk8qj5/81046099413.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE15 5324 bytes
SHA-256: ddacbec51444bff34bd20fd37177626ac2b5e966b7966052222f319d54041198
font_01_sfnt_off0000eff6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF6 10672 bytes
SHA-256: d5fe49faef6101fef0e1c1c010cdb63b3adecdcbde98006cb6bcec14cfab4e14