Malicious PDF — malware analysis report

Static analysis result for SHA-256 83f034edb5d9ae5e…

MALICIOUS

PDF

74.8 KB Created: 2021-11-14 07:52:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 52bfb9246bddc12c56437e9d4dd776e8 SHA-1: b83ebe401b0e689cd631143a0f55c70c5ee275dc SHA-256: 83f034edb5d9ae5e3eaf13bbc1add0d6f4e1a91915b2921573867ed0ca7688e4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to phishing or malware distribution sites. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure points to a link farm designed for malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613c98ede36b7---ziveb.pdf In PDF document text
    • http://www.vishalsahni.com/public/ckfinder/userfiles/files/loxamalija.pdfIn PDF document text
    • http://greenworx.eu/images/uploads/files/86996143079.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/gejawazazamo.pdfIn PDF document text
    • http://7serve.org/userfiles/file/20210918162108.pdfIn PDF document text
    • https://dalnoboy.com/data/filestorage/upload/files/fonurevuvugi.pdfIn PDF document text
    • https://aqua2go.pl/galeria/file/somoxoveregamoxu.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161746bc3c9bc9---latamedamisowijaximo.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/2021922154256956.pdfIn PDF document text
    • https://reha.bg/content/upload/file/matipak.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/161815ddf9ea9a---geluxukemigix.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/94656399707.pdfIn PDF document text
    • https://thegioibaobicarton.com/Images_upload/files/92183297718.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/zijisifewob.pdfIn PDF document text
    • http://tlcjty.cn/userfiles/aa/file///vosakedaseguwebivori.pdfIn PDF document text
    • https://ezastupitelstvo.sk/editor_uploads/system/files/11796350747.pdfIn PDF document text
    • http://vicc.huh.hu/UserFiles/File/30352302885.pdfIn PDF document text
    • https://ww150006.linebot.net/upfile/files/20210922011001.pdfIn PDF document text
    • https://ladymamashop.com/uploads/files/202111060152416104.pdfIn PDF document text
    • https://sacc-la-chaux-de-fonds.ch/fichiers/file/jumizanora.pdfIn PDF document text
    • https://buyafranchise.org/files/files/39507740360.pdfIn PDF document text
    • http://thucphamchucnangmy.vn/uploads/files/guriwebuviwunifovof.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/cmwvf4RlXg4/uplcv?utm_term=hydrotherapy+book+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_off0000c09a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC09A 17728 bytes
SHA-256: a3e584bee5b45f305a58833346d7c239bc3afda9b18af31b58589bd6ddb23463
font_01_sfnt_off0000eecb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEECB 10520 bytes
SHA-256: 03a9ae29afa5099209cde926fd7730af17ad2b6c7da1df19b54acb556288fba4
font_02_sfnt_off0001069f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1069F 16540 bytes
SHA-256: 45015263e28dbf00792e0fa83ae0fb9123af5110209f191c00797c49350166ef