Malicious PDF — malware analysis report

Static analysis result for SHA-256 31de8f2eb2bcc4d7…

MALICIOUS

PDF

86.2 KB Created: 2021-09-10 00:49:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7062d94c9a4493777f24fa34e2943851 SHA-1: 2be66e0c97a8716a608536ef850d1edcfc58b4a8 SHA-256: 31de8f2eb2bcc4d795973e20df228fbbb65760439f7b7b1cfc25380d7b237f3d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and link farm heuristics indicates an attempt to lead users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://coretry.ru/uplcv?utm_term=list+of+all+launchers+for+android PDF link annotation
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/lajagidipumafugunujope.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/161337fc74fde0---kofedef.pdfIn PDF document text
    • http://redskap.ru/userfiles/file/46992382318.pdfIn PDF document text
    • http://generoussecurity.com/uploads/22022918579.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613958b2d4b6e---nakonukigemunimibume.pdfIn PDF document text
    • http://xn--2e0b30g3uq7pay7m.com/upload/fckeditor/file/47530388317.pdfIn PDF document text
    • https://ngonluathan.com/images/ckeditor/files/katofiw.pdfIn PDF document text
    • https://gadesign52.com/uploads/files/202109032119344858.pdfIn PDF document text
    • http://toszegisuli.hu/userfiles/file/kifepegolasuwerovid.pdfIn PDF document text
    • http://klm-co.ru/foto/ck/files/tikevimakirutomedujenuxo.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161355744c95b9---39948230178.pdfIn PDF document text
    • https://thanaclusterwestgate.leaddeehub.com/userfiles/files/88627422561.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efd871638a---15440697483.pdfIn PDF document text
    • http://sinocelltech.com/filespath/files/20210909204546.pdfIn PDF document text
    • http://robvancampen.nl/userfiles/file/18046322397.pdfIn PDF document text
    • https://tranhtreo.com/images/ckeditor/files/44157794729.pdfIn PDF document text
    • http://hadt.vn/upload/files/wajugofoxewuj.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16137fbdec85ad---11697962332.pdfIn PDF document text
    • https://serpavenger.com/ckfinder/userfiles/files/28687362328.pdfIn PDF document text
    • http://doubler-son-capital.com/photos/files/wepavaxuzozupak.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/13975621671.pdfIn PDF document text
    • http://sushrutproctology.org/ckfinder/userfiles/files/mukobiredo.pdfIn PDF document text
    • 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_off0000ecc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECC3 10628 bytes
SHA-256: cc2b904328ee844ffe6832193c46b254e715ecf0d17e827839b14ff4e8194ff2
font_01_sfnt_off00010501.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10501 18044 bytes
SHA-256: 295cc3845baffeacaf70cc8641d4a63deed6d094c52bf622eac86ec5f0ffbb54
font_02_sfnt_off00013378.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13378 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1