Malicious PDF — malware analysis report

Static analysis result for SHA-256 53fc931d6226a493…

MALICIOUS

PDF

85.3 KB Created: 2021-09-18 18:07:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: df57c6fc4fb7c5173dbbfec2e4f05935 SHA-1: 0860892129118169832b07290de87ca85fe15a99 SHA-256: 53fc931d6226a493c950a0d5239d0798a423e33e92a9d72d6eb9cb2fa7dea2b5
126 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics, including a high ML score and ClamAV detection as a phishing trojan. It contains numerous embedded URLs, many pointing to domains that appear to be part of a link farm, suggesting an attempt to obscure the final destination or distribute malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically indicates a non-clustered link farm on disposable hosting, reinforcing the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://sdudyogtechnologies.in/ckfinder/userfiles/files/34356102986.pdf In PDF document text
    • http://keifo.ru/ckfinder/userfiles/files/tereripezipabavumekila.pdfIn PDF document text
    • http://zzzwchem.com/upload/files/2594091218.pdfIn PDF document text
    • https://horacebatten.com/ckfinder/userfiles/files/29860776735.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/40210871915.pdfIn PDF document text
    • https://clinicaabrahaoosta.com.br/ckfinder/userfiles/files/valedulet.pdfIn PDF document text
    • http://lonerangerfanclub.com/ckfinder/userfiles/files/pilugegoxujazumufikemifi.pdfIn PDF document text
    • http://zentrumok.com/userfile/files/wakanetaxexoxopiwu.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/zavarenobibezabawunaforuv.pdfIn PDF document text
    • https://ip-kamera-rendszer.hu/ckfinder/userfiles/files/tagopofok.pdfIn PDF document text
    • https://www.studioline.ie/ckfinder/userfiles/files/13795051740.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130b4b2a6818---zuvogujusojepopivamel.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/70621153063.pdfIn PDF document text
    • https://drlalashow.com/php/billboard/uploads/file/lalajadojepin.pdfIn PDF document text
    • https://bolahijau.com/contents/files/rojobo.pdfIn PDF document text
    • http://drukarnia-skawina.pl/app/webroot/media/files/68626897361.pdfIn PDF document text
    • http://wpchkg.com/upload/image/file/30991203071.pdfIn PDF document text
    • https://www.tocbirsen.org.tr/ckfinder/userfiles/files/39841669917.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/xeliguj.pdfIn PDF document text
    • http://thepducphat.com/upload/files/jipanagapedakilakivopu.pdfIn PDF document text
    • https://haruhonpo.com/upload/haruhonpo/files/zumexowejuveweju.pdfIn PDF document text
    • https://ezsprinting.com/userfiles/file/kolalomesamofuzerikedi.pdfIn PDF document text
    • http://mobilni-kadernictvi.cz/files/file/junizidagi.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/nedewetuju.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=link+android+phone+to+chromebookPDF 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_off0000e8bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8BF 17620 bytes
SHA-256: b611d26eb64ab59b9663bfde771c971fe66e290d67d98864c7a87ca84d5db5d6
font_01_sfnt_off000116cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012ee4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EE4 10752 bytes
SHA-256: 4f47107f908d70ca61526f150f2207669a7fa8b628ddfa235c1d54debdb200c1