Malicious PDF — malware analysis report

Static analysis result for SHA-256 83373fd8244d8887…

MALICIOUS

PDF

80.5 KB Created: 2021-09-05 04:51:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c675d32ad2d42574250989b9aae6bbce SHA-1: 36418e5d548fb3afbd8a4d015f46c7b1de57707f SHA-256: 83373fd8244d888760626d007f09e8a196bd2766d6b26769c7f15ba569fbb8f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised CMS uploads or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, classifying it as a phishing trojan. No scripts were extracted, so the primary attack vector appears to be the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://kgmda.com/upload/files/4997115811.pdf In PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/9251104e4674a9c7e838d27844c36306/95706149383.pdfIn PDF document text
    • http://pensacolahigh1964.com/clients/1/1d/1d652d7f5bd5fd2f3712913460b20393/File/sajewo.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d132b80ca---dagefesabako.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/1424096240.pdfIn PDF document text
    • https://bibliothequeanglaise.org/upload/files/79942373860.pdfIn PDF document text
    • http://kamkmori.cz/ckfinder/userfiles/files/waxoxunuvelulij.pdfIn PDF document text
    • https://srinivasagroup.com/ci/userfiles/files/27229010341.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160a15798194f5---12373808576.pdfIn PDF document text
    • http://wingprocess.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/4916932547.pdfIn PDF document text
    • http://kolasinprevoz.rs/slike/files/regiteberadivilefe.pdfIn PDF document text
    • https://duragloss.pl/userfiles/file/zapofubukomixozanifu.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/7f357896ff148c4edf22c04aa2a52c82/82637786713.pdfIn PDF document text
    • http://kovacsoltvaskerites.hu/images/file/rakanebuwoloxawi.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/qn7khj2k4fualj1ts3sh3ajl9k/wibodetakonituv.pdfIn PDF document text
    • https://reformedgeneration.com/userfiles/file/vowimowiraperiwusa.pdfIn PDF document text
    • http://noithatphathuy.com/Images_upload/files/pexupuzenasamegajujuvenis.pdfIn PDF document text
    • https://www.prestigeautobody.com.au/wp-content/plugins/super-forms/uploads/php/files/ab81ad97394adcab6601af6e9b3c051d/fesamoguruxu.pdfIn PDF document text
    • http://es-manzokudou.com/yamituki-n/uploads/files/77045367186.pdfIn PDF document text
    • https://nhachoxebus.com/upload/fck/file/32918967814.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/92106078601.pdfIn PDF document text
    • https://ikitellirezistans.com/upload/files/pujofezamivijevamatujep.pdfIn PDF document text
    • http://quadocdao.vn/uploads/files/35717634310.pdfIn PDF document text
    • http://standrewsparishhighschoolclassof1964.com/clients/70428/File/depuvelolo.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607daa8ddc7a4---lalosurixubavamatofeko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=making+words+lessons+first+grade+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_off0000d5ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE01 10844 bytes
SHA-256: 13746bae5a24696c695317afad4c6da6ab8d237317d636c5a3652a66d282f72a
font_02_sfnt_off00010701.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10701 17372 bytes
SHA-256: 6d3957ed5db6bcf398598c9b4ee382759a5bbb6f801ae79be0d6fcaf4306305b