Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c4d40bec8a63c80…

MALICIOUS

PDF

79.0 KB Created: 2021-09-20 03:17:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a5ac2539dd5a7e52cfe0feee34c29260 SHA-1: 011e139a063462b35eb967863e072d963e64ac3f SHA-256: 7c4d40bec8a63c802a3677e8699c0a9ef1993e7e2ed24412bee63986a7a4e7ed
134 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous embedded links, many pointing to PDF files hosted on various domains, and a heuristic identified a 'download button' lure. This suggests a phishing or social engineering attack aimed at tricking the user into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614094c1b544c---39866002371.pdf In PDF document text
    • http://www.cbs-emballages.com/upload/file/pabikawosekozelolofu.pdfIn PDF document text
    • https://philly.drinkpoint.com/uploads/files/81776916028.pdfIn PDF document text
    • http://bloodfaces.de/attachment/file/7493076385.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613e52637f32e---93051051139.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/2985574898.pdfIn PDF document text
    • https://vicotelecom.vn/static/source/images/file/kovadadizemoxekoloko.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/49043483694.pdfIn PDF document text
    • https://zlato-invest.cz/upload/files/73548376874.pdfIn PDF document text
    • http://misterholidaysanprisco.it/userfiles/files/44741711719.pdfIn PDF document text
    • http://travellightnepal.com/userfiles/file/kizum.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/muziwimig.pdfIn PDF document text
    • http://alothongtin.com/upload/FCK/file/dizewotusiponavavuj.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/luviwevu.pdfIn PDF document text
    • http://keyday.ru/files/files/dowoxuxezapuzogelefawak.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/73546839302.pdfIn PDF document text
    • https://lifetides.ca/cambridge/uploads/files/fegejufonavesoruget.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/nojoxowejegifan.pdfIn PDF document text
    • http://benardoutlite.com/admin/fckeditor/fckdata/file/nekopunenumeji.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/58274707119.pdfIn PDF document text
    • https://havilahbuilders.com/userfiles/file/mipuwufipu.pdfIn PDF document text
    • https://groupburuemas1.com/contents/files/didavu.pdfIn PDF document text
    • https://globalybm.com/ckfinder/userfiles/files/1630975729.pdfIn PDF document text
    • http://rancholasmonturaspremios.com/campannas/file/xomenikokaza.pdfIn PDF document text
    • http://klm-co.ru/foto/ck/files/lezevogat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=drastic+cheat+filePDF 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_off0000cfcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFCB 18128 bytes
SHA-256: 35299b9298e8f9cc17bb096e0251510009ec7bb5a585af3657a999050c2accb5
font_01_sfnt_off0000ff05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF05 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001171c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1171C 10208 bytes
SHA-256: e76ba7bccebd88efad1e309a2995e8ed8bdf83553825fbc7fbf2dd1d5f3f436d