Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d166656bd57bbf6…

MALICIOUS

PDF

82.3 KB Created: 2021-09-24 06:47:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d582fb8ace12270c9802062fa53a4a92 SHA-1: dd39a836ea70c0cb71357a189978f16c5aeca133 SHA-256: 4d166656bd57bbf6205938fd84bd0ff40976aedf8eae6acccb61683b8774f19e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with attempts to redirect users to malicious sites, potentially for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://ketchas.ru/uplcv?utm_term=best+app+to+convert+pdf+to+epub PDF link annotation
    • https://inprovitchile.com/ckfinder/userfiles/files/26511788853.pdfIn PDF document text
    • http://candybeauty.vn/upload/files/jisif.pdfIn PDF document text
    • https://www.edmcenter.xyz/ckfinder/userfiles/files/97468187789.pdfIn PDF document text
    • https://willes-gb.com/uploads/files/202109010850267205.pdfIn PDF document text
    • http://carrasvilla.es/uploads/files/89224271683.pdfIn PDF document text
    • http://discus-rus.ru/upl/file/ganadefofoxusaxo.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/0a84a0af35576b98c99de600e4a59772/22278583569.pdfIn PDF document text
    • http://leadingedgecorporate.com/user_images/file/40713574528.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161333cd86951f---mezojedifasuzotokidukiwir.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/60450683219.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132551bac085---15289429386.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/dexiwirewup.pdfIn PDF document text
    • http://timecraftz.com/userfiles/file/fuvutugukilanisimab.pdfIn PDF document text
    • http://dj-maily.com/uploads/pages/files/24780107836.pdfIn PDF document text
    • http://vinhthuanvietnam.com/upload/files/benimupizelidesitudamazi.pdfIn PDF document text
    • http://villalapinetafavignana.it/userfiles/files/kuzalefimibijukaf.pdfIn PDF document text
    • http://westfield.qa/multimedia/userfiles/file/62951023855.pdfIn PDF document text
    • https://rowadalbyt.com/userfiles/files/pobepuvibuzafotuvojolu.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/20219161322466860.pdfIn PDF document text
    • http://citygclub.com/ckupload/files/394682377.pdfIn PDF document text
    • http://rem-stroymont.ru/img/file/fibijilona.pdfIn PDF document text
    • http://apsencollege.org/test/fckeditor/file/88132495570.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_off0000dba4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BB 10832 bytes
SHA-256: d47cdd89d380d309fad73909737d2517c042f081435ccf3fc1957ad8525bb0b6
font_02_sfnt_off00010cbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBB 18104 bytes
SHA-256: 8f60a2aa281a3d097ea66cd105a1bc1b3dd1621558dc172ab1fa66168b8f68f9