Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dd23a265cc66ce0…

MALICIOUS

PDF

82.8 KB Created: 2021-09-18 08:51:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0c8499490a9f1af3870beb383861f575 SHA-1: 9ca7207d8dcdf0959e1d72d4b36a19bb4b4423f4 SHA-256: 4dd23a265cc66ce05001c615d3cd532e5628213d3ec79aeccb63ffb7aaa7200c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. The primary goal appears to be to redirect users to malicious content or phishing sites, leveraging techniques like SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://somos.co/dleyes/admin/fotos/file/rorutigerubapojevutowuxi.pdf In PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/35837845257.pdfIn PDF document text
    • http://ydis.kr/userfiles/file/060819317309.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161352a9832326---kamamuvemuvowogejenakapur.pdfIn PDF document text
    • http://armanetti.com/images/53496450596.pdfIn PDF document text
    • https://ka-base.no/images_students/files/mekisavi.pdfIn PDF document text
    • http://geopraxis.it/userfiles/files/2765849058.pdfIn PDF document text
    • http://leton.pl/userfiles/file/fisopejezejugumoxene.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16141a1e531218---20605615232.pdfIn PDF document text
    • https://pmeds.us/userfiles/file/81284097910.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210905205710131.pdfIn PDF document text
    • http://sutipatika.hu/userfiles/files/60438669370.pdfIn PDF document text
    • http://kledingindex.nl/images/uploads/47079663803.pdfIn PDF document text
    • https://butterfly-propertymanagement.com/userfiles/file/36579005195.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/0c301080fc08686d9fef49371cc27d0b/logefunikenumatisiru.pdfIn PDF document text
    • https://artbynela.com/uploads/file/fafulafujum.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6695d2dcc---19623159235.pdfIn PDF document text
    • https://jasz-pap.hu/UserFiles/file/bozerogegifanitegil.pdfIn PDF document text
    • http://solmoda.it/userfiles/files/zodofod.pdfIn PDF document text
    • https://www.amata.org.uk/ckfinder/userfiles/files/95825809609.pdfIn PDF document text
    • http://baheth24cars.com/ckfinder/userfiles/files/97271139267.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/d4a29af2d6e89a74a09f7aaa99a390aa/sezasowowomewet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=what+is+the+name+of+new+android+versionPDF 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_off0000ddf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f60e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60E 10716 bytes
SHA-256: c040f751fc44e4ae0fa92f5ac53e00bc5b0ebf7a79900fbec862bc92e8d5f234
font_02_sfnt_off00010e8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E8B 18080 bytes
SHA-256: f8bd22be00a2eac40e7b4968b13db9c81cd0e4962c57ab2f49348f57f63d496f