Malicious PDF — malware analysis report

Static analysis result for SHA-256 857b654ffdac86ba…

MALICIOUS

PDF

74.6 KB Created: 2021-09-14 06:12:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: dcf0bb77e7eda68359537c164b79b2c7 SHA-1: 8a6dfbc9f14cddc06db91b0705026f3b4ce152d7 SHA-256: 857b654ffdac86baf95c7d6969d2ada5acd0d834c15a4ca4525fac7f2d9d25cd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to compromised CMS upload storage, suggesting an attempt to trick users into downloading malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • 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://villalapinetafavignana.it/userfiles/files/10737590207.pdf In PDF document text
    • https://tselectromechanical.com/uploads/CKfiles/files/bujukezojobajuzukek.pdfIn PDF document text
    • https://hse.tw/upload/file/40096653460.pdfIn PDF document text
    • http://stressmanagement-karriere.de/userfiles/file/jowul.pdfIn PDF document text
    • http://markone-tools.com/upload/files/75353334317.pdfIn PDF document text
    • https://iva-vietnam.com/userfiles/file/zirerisovenofifer.pdfIn PDF document text
    • https://premiersuli.hu/files/files/nupusodafazogujawuzawepik.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cec7ac6c1b---60000753831.pdfIn PDF document text
    • http://capital96.com/userfiles/file/97187231093.pdfIn PDF document text
    • https://netwindowvn.com/uploads/userfiles/file/67816578289.pdfIn PDF document text
    • http://apex-architect.ru/images/file/ginamunuwojazajedibu.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/99694123387.pdfIn PDF document text
    • https://bcbc3399.com/upload/files/50219055737.pdfIn PDF document text
    • https://escolaalfa.com/userfiles/file/98439245846.pdfIn PDF document text
    • http://leton.pl/userfiles/file/juferuzominasafimowegiw.pdfIn PDF document text
    • http://2safe4u.cz/UserFiles/File/bolisolusapepapewim.pdfIn PDF document text
    • http://ridendo.cz/files/file/tunejewak.pdfIn PDF document text
    • http://visit-pune.com/userfiles/file/rujosetodevozineworu.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16130c00695315---18789198361.pdfIn PDF document text
    • https://egokituz.eus/files/galeria/files/47142560890.pdfIn PDF document text
    • http://way-of-spirit.ru/upload/file/nerabelifaxaputuritikiwun.pdfIn PDF document text
    • http://balone.net/_upload/file///vewisuwinakedivogusef.pdfIn PDF document text
    • https://hanoihome.net/img_duhoc/files/99627004864.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe04c71554---33785307885.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=krunker+aimbot+steamPDF 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_off0000c096.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC096 10544 bytes
SHA-256: 4ec477cf02cab187d125479c4396e4ed75e6fd3583af97b36417ad701cc7937f
font_01_sfnt_off0000d8a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f0b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B7 16892 bytes
SHA-256: 6479c4f4adabf18f970688155eb55edef8570908d69771bc8b9f55d2c848dd77