Malicious PDF — malware analysis report

Static analysis result for SHA-256 31d7a91ca2362f17…

MALICIOUS

PDF

74.6 KB Created: 2021-09-03 03:03:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b17353e02f56556874bacbec4da6cde5 SHA-1: a0eb4551c5fceab25d8f6befb0de9121df2dc455 SHA-256: 31d7a91ca2362f17b3f2e1dd355384be5214e1f2842b2c59644c0cbe9ed9d8d7
196 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal malformed streams and multiple URIs pointing to compromised WordPress uploads, suggesting it acts as a lure to download a second-stage payload. The presence of numerous links to potentially compromised CMS uploads indicates a pattern of hosting malicious content on such platforms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://www.restaurant-latableedevercel.com/ckfinder/userfiles/files/mopopa.pdf In PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/daxumubasafux.pdfIn PDF document text
    • http://namhungholdings.com/uploads/ckfinder/files/jazadafekuzag.pdfIn PDF document text
    • https://calson.garment-pro.com/ckfinder/userfiles/files/rugomusodevijogeg.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/83424755442.pdfIn PDF document text
    • http://womenshealthcarenp.com/clients/2/29/29a32d4da59f0b4eaa4573e1354aeabc/File/24142889564.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/8f06baaf67d012b031ee220316a905aa/nuroresuremodesalule.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f1547a8dec6---84268657899.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/16082fe7aebe65---10026003813.pdfPDF link annotation
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160846b8b171b4---32215201612.pdfIn PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/28nqkgaflq0gra6fv2pftm51g9/tugutuf.pdfIn PDF document text
    • http://1night2daytour.com/ckupload/files/45216931299.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160724f041f11d---siwobolovuw.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210705172613252.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/4ummg6qi7r3r0jngnt4bflk253/33597996408.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/160765ceeda988---fanetisodowameg.pdfIn PDF document text
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/f6vng40pb9n6d06js8eua93dad/vuwegazajifazikavawovilut.pdfIn PDF document text
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/633e5d45ed82827ea8433b3d24158149/12420165660.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b47cc2094cd---lisenotarifutolimodepofif.pdfIn PDF document text
    • http://royalleasingny.com/admin/images/file/38152117215.pdfIn PDF document text
    • http://foto-klub.dk/userfiles/file/47302028651.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=imperative+sentences+worksheets+grade+2PDF 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_off0000bd81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD81 17512 bytes
SHA-256: 771e6d54517f67be22f8ec8a8399d6f609c38d090a1e044e21274cf34f167b93
font_01_sfnt_off0000eb00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB00 11228 bytes
SHA-256: eebdec9f7752bb6e73736ec444a2c79cbedc963fb7afe6a388dccb924d4ae2d6
font_02_sfnt_off00010509.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10509 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1