Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ba3195c00b4a90…

MALICIOUS

PDF

73.9 KB Created: 2021-09-28 04:45:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6d78cc5a4d0ca6003d82346e7c42a5c7 SHA-1: 8f09b39d0a03757bba11f0d69f3861f001f3bcba SHA-256: 81ba3195c00b4a907a70bdf1a001d1217b82072c4f7b390d25c6857d063c08c1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to potentially compromised websites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the nature of the links and the PDF structure point towards a malicious document, possibly leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

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 https://oniceh.ru/uplcv?utm_term=camscanner+2019+apk
    • http://opuspointpartner.com/ckfinder/userfiles/files/14891803547.pdf
    • http://kingtonkatsu.com/uploads/files/11835224775.pdf
    • https://sanaspinler.net/calisma2/files/uploads/fafuxijadofenixijini.pdf
    • http://exim5.hu/_user/file/jilajoritite.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/d0jajfncjh7sid2ce865dq80ss/26727272150.pdf
    • http://gayaarchi.com/userfiles/file/20210927004513.pdf
    • http://www.deep2001.com/images/library/File/kefizedikimufarijoxoti.pdf
    • http://baovecongtruong.com/upload/files/25629133085.pdf
    • https://ganport.pl/userfiles/file/27245195249.pdf
    • http://cosmeticdermatologymiamibeach.com/uploads/data/files/85801606685.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/bc0cfb0eb77c9d78d23f40c115009832/fusepidu.pdf
    • http://liccuza.ro/stiri_files/file/gavomifelogivemopolosak.pdf
    • http://baracenter.be/userfiles/file/jamemuvarowisuviwume.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161494d584017c---97335394972.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614bcfafaa822---538282652.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613d338202dc3---kurutopopadat.pdf
    • https://ost-fogging.com/upload/files/80536243963.pdf
    • http://cloverdiamond.com/file/vexatapiri.pdf
    • http://www.jasfec.com/imgs/uploads/93835040757.pdf
    • https://hanurichurch.org/ckfinder/userfiles/files/34732940928.pdf
    • http://etcad.net/np/upfile/file/48140913843.pdf
    • https://zufiks.pl/uploads/userfiles/files/76465733661.pdf
    • http://aaz.sk/editor_uploads/files/45129912720.pdf
    • https://zd-zeta.com/uploads/files/202109070356137590.pdf
    • https://bahamianbrewery.com/ckfinder/userfiles/files/16334394676.pdf
    • https://dance-lab-new-delhi.com/userfiles/file/23129221617.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b928.bin
b9eb210e150370bb94b1590bd9ce92f92b0e73f618fdc61e5ae5936ac2399805
pdf-font-stream PDF embedded font (sfnt) at offset 0xB928 18496 bytes
font_01_sfnt_off0000e919.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE919 16792 bytes
font_02_sfnt_off00010130.bin
9cb1bd27899e59871a910823d76d860f376a5fa8f764e345e3739ad6a0a8e438
pdf-font-stream PDF embedded font (sfnt) at offset 0x10130 10764 bytes