Malicious PDF — malware analysis report

Static analysis result for SHA-256 bca7d8447b293a81…

MALICIOUS

PDF

84.8 KB Created: 2021-09-04 06:03:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 2b124a289249fd3c83328f6c29258cf9 SHA-1: 2a2ad92363a9a8ffc9d528426d332d7f5267df8f SHA-256: bca7d8447b293a81c580b4c0a94606eb50f5ae66ae90db0eb159f24ce55874f9
156 Risk Score

Malware Insights

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

The PDF was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of multiple PDF link farm heuristics further supports this assessment.

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 http://take114.kr/FileData/ckfinder/files/20210729_CE70343FA3BA95A9.pdf In PDF document text
    • https://bitree.com/ckfinder/userfiles/files/kupujirexosife.pdfIn PDF document text
    • https://cailux.lu/userfiles/files/69737165030.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d60b89c7a---84250864812.pdfIn PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfec6945c1d---nijagukufaba.pdfIn PDF document text
    • http://targdenunti.ro/userfiles/file/36290980026.pdfIn PDF document text
    • https://speak82.com/_UploadFile/Images/file/tadajupe.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/160a5f519e26c1---nuxukijodimakitax.pdfIn PDF document text
    • https://ratosatu.com/contents/files/45461241586.pdfIn PDF document text
    • http://cambresisemploi.fr/ckfinder/userfiles/files/bukifi.pdfIn PDF document text
    • https://ooobelkom.ru/ckfinder/userfiles/files/jebedetujeponulozolafik.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/ckfinder/userfiles/files/18811257492.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edb8c35a399---zuxadowibezuxezesepis.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160848a56d3b5f---minepudorutimotawolirebu.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/66cd433ca2bccb4991cde4a6d2d476aa/79976395149.pdfIn PDF document text
    • http://www.afurg.com.br/assets/ckfinder/userfiles/files/62767513097.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/k1kggrgp8lv692qs3d1k2vast3/komefupasapoxote.pdfIn PDF document text
    • https://btcauction.vn/hinhanh/file/93123112835.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/2832541109.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/ke3g3ev7djh2ndct4s7thef261/dulugerinavixum.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/15578329366.pdfIn PDF document text
    • https://frontivo.ro/userfiles/file/10718034714.pdfIn PDF document text
    • https://gea99.com/ckfinder/userfiles/files/romenowodutamotorilewab.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/21f862dddc76844afbcfbc6db6dcdf12/25723456170.pdfIn PDF document text
    • https://unique-u.biz/images/uploads/file/39289435409.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=symbolism+in+the+scarlet+letter+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_off0000e516.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE516 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD2D 11216 bytes
SHA-256: 48ca6c5cd2991c823a470d46f0b2a4d64776b94ffcc93f788d64e5289b40a32e
font_02_sfnt_off000116fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116FD 18164 bytes
SHA-256: e32394a20ae5bb9d107eef436351518389089848cde4a628cdac1c00e34ff94a