Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b4c92a703d4885…

MALICIOUS

PDF

81.7 KB Created: 2021-09-21 08:44:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d680cf2ca300564987708f0b00a575f7 SHA-1: 9e8c8c592e146c6bf52a99f0933a99071582f152 SHA-256: 85b4c92a703d48855edbf8a541f7d94bda3d56de4741e31d70ef0a39643fc786
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. The presence of embedded URLs and the heuristic firings related to link farms and compromised uploads point towards an attack pattern focused on redirecting users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://philabc.ru/uplcv?utm_term=fortnite+android+phone+list
    • http://elektrostroy.kz/ckfinder/userfiles/files/bubezavi.pdf
    • https://sim2007.com/files/68002393878.pdf
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/lejibutufo.pdf
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/5b0d96c79b355db2fe56ce114d118de2/16901505284.pdf
    • http://2478.ru/admin/ckfinder/userfiles/files/72836379467.pdf
    • https://reha.bg/content/upload/file/xatepenufubixulofa.pdf
    • http://contextuae.com/resimler/files/putufugen.pdf
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/b8hfmua08hub4n83eachjk6o41/vibapifuwukoga.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16138e4e2ad419---13718266236.pdf
    • http://pamatudarbai.lt/ckfinder/userfiles/files/zilikidow.pdf
    • http://tw-tms.com/uploadpic/xw/files/21873991532.pdf
    • https://magnumattachments.com/ckfinder/userfiles/Files/60985625437.pdf
    • http://yousefmaktabi.com/ckfinder/userfiles/files/zemekidinutumapefavu.pdf
    • https://relaxbotanika.cz/ckfinder/userfiles/files/79902164533.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141cfb20956f---pokofemarozivamofora.pdf
    • http://24hnbc.com/assets/ckfinder/core/connector/php/uploads/files/wewenexovezelabovemawi.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/161437e5f8720f---kigoliratidekogisin.pdf
    • http://diakmelo.hu/ckfinder/userfiles/files/kapibulofo.pdf
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613984bc57ea7---gisokawudesosudev.pdf
    • https://muahohangnhat.com/app/webroot/uploads/files/pilex.pdf
    • http://vervesimuhub.com/userfiles/file/jewibakegafi.pdf
    • http://danguykhoidoanhnghiephp.vn/Upload/files/bedak.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613815bf53d08---39309820546.pdf
    • http://ambulatorioveterinariocigliano.com/userfiles/files/ribopolaretimizisat.pdf
    • http://floridadressyourhome.com/uploaded_files/userfiles/files/towig.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db64.bin
86868c7f36a22847e9297653f079c4ba81636f2f2aa99e8f3c16bb3cf63643c8
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB64 10464 bytes
font_01_sfnt_off0000f2fd.bin
229da0fe3208d03ceffc07dd5f82fca0f9a19958353644e204f83ef54e331a03
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2FD 17664 bytes
font_02_sfnt_off000120f0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x120F0 16792 bytes