Malicious PDF — malware analysis report

Static analysis result for SHA-256 39140a906a38722f…

MALICIOUS

PDF

79.0 KB Created: 2021-09-16 09:48:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 935b5d84542f95672d536857f7128135 SHA-1: fd5ecb4134829620568968558a6e4e56d3ab6bb2 SHA-256: 39140a906a38722f436bf35213654c2860930152c072b2076ceb4ae0fac3c611
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various PDF files hosted on different domains, indicative of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is an SEO poisoning or content spamming operation. While no scripts were explicitly extracted, the ML classifier and ClamAV detection point to malicious intent, likely involving the exploitation of PDF vulnerabilities or the delivery of malicious content via the linked PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://bliznacite.com/files/84289455627.pdf In PDF document text
    • http://mueblesdepladur.es/1/userfiles/file/zevegijezanudesu.pdfIn PDF document text
    • https://bongkartuantakur.com/contents/files/27119743588.pdfIn PDF document text
    • http://aalzkj.love-mrt.com/upload/files/noruja.pdfIn PDF document text
    • http://oawebserver.com/piceditor/file/gimulit.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134f69e1bca9---sadakivigixesepusofag.pdfIn PDF document text
    • http://a-pro-peau.fr/userfiles/file/43821876714.pdfIn PDF document text
    • http://uniquehotelsolutions.com/files/others/nepuxosewomado.pdfIn PDF document text
    • https://www.gico.ge/ckfinder/userfiles/files/gubuvunomikesefegimal.pdfIn PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/96567221599.pdfIn PDF document text
    • http://paradisoseminatrici.it/userfiles/files/87049832292.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/10472266369.pdfIn PDF document text
    • http://mywayrtk.org/userfiles/file/zofopi.pdfIn PDF document text
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/5833142971.pdfIn PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/dexuvifuxaze.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/16130cc8fbf04f---4289947357.pdfIn PDF document text
    • https://nocnepal.org.np/ckfinder/userfiles/files/9269333378.pdfIn PDF document text
    • https://yodobashi-church.com/41388596288.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/kakotanofekoz.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/3610264570.pdfIn PDF document text
    • http://turatabor.hu/media/18440968236.pdfIn PDF document text
    • http://beiwendq.com/data/attachment/file/41503733288.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=efootball+pes+2020+android+apkPDF 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_off0000d057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD057 10948 bytes
SHA-256: 4b4c6926dc8646a3e810769c2921233c9ca933e0bf9fbc237c8ed4a042ea4f1a
font_01_sfnt_off0000e9a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A2 17360 bytes
SHA-256: 16a67ba0a1cf27bc37c630bfbac5a260c1c5747fd964249fcd5f6a2519b96675
font_02_sfnt_off000116c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1