Malicious PDF — malware analysis report

Static analysis result for SHA-256 55817cbdc67f197f…

MALICIOUS

PDF

82.0 KB Created: 2021-09-04 05:45:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 103b5f1ae41c41ccc981bff23760650e SHA-1: 9c76557270f18990a04ba0bb4ad1f8ec00ecf519 SHA-256: 55817cbdc67f197fa5bf125b4747dc593fb18b8275e47f0f0c5763c98c19a33f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to websites hosted on compromised CMS platforms or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The primary attack pattern observed is the use of a link farm to direct users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://screen.by/images/file/91350823121.pdf In PDF document text
    • http://www.trotasierra.com/plugins/ckfinder/userfiles/files/bosuxixuwojisutuw.pdfIn PDF document text
    • http://jwnorthclassof70reunion.com/clients/c/c6/c6167e942b76adab5863fbee8ae727a7/File/nekigenako.pdfIn PDF document text
    • http://greenhousehotel.vn/uploads/image/files/11155213646.pdfIn PDF document text
    • http://logiccpacma.com/ckfinder/userfiles/files/mewekoxorelo.pdfIn PDF document text
    • https://rieker-consulting.eu/files/file/zuwatuloropodesowinusa.pdfIn PDF document text
    • http://ledspectrumthai.com/ckfinder/userfiles/files/97932436671.pdfIn PDF document text
    • https://mehreganimaging.com/images/upload/files/lepubigaw.pdfIn PDF document text
    • http://arch-teh.com/pic/userfile/rasapikivasewividifobena.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/52698095851.pdfIn PDF document text
    • http://geopraxis.it/userfiles/files/dalakugekinadami.pdfIn PDF document text
    • https://grupo-bahia-real-estate.com/ckfinder/userfiles/files/44518111997.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1606e558c56c8c---9460788461.pdfIn PDF document text
    • http://greenbrier101.com/userimages/72235813194.pdfIn PDF document text
    • https://otartufo.com/ckfinder/tartufofiles/files/luwuxarudumekem.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090533b5dbf4---jufifasuzatinogusano.pdfIn PDF document text
    • https://www.alignerco.ca/wp-content/plugins/super-forms/uploads/php/files/81df9187fd9abd75b505b8c0725a7c84/97310875946.pdfIn PDF document text
    • https://blugarden.eu/file/firenofarevefanovid.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160eca0d97e86c---11047150500.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/49806635284.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/pupozezexemexafegafovimuz.pdfIn PDF document text
    • http://xn--9d0b102a6wc3y4a.com/sa_upload/userfiles/file/20210705220421.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=types+of+organisation+pdfPDF 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_off0000dcb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCB8 17552 bytes
SHA-256: 9e5c320c8b1a29f99a1dddbe13caa6f47d020250eef133a134dbc795cc696944
font_01_sfnt_off00010a36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A36 10704 bytes
SHA-256: 945b85267a6f8ed64e403f44bdebde5727dbff8229b52501246532ea6021249a
font_02_sfnt_off000122c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1