Malicious PDF — malware analysis report

Static analysis result for SHA-256 824bcea21df66ec0…

MALICIOUS

PDF

78.7 KB Created: 2021-09-14 15:43:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d17b328e2c02ebb487ee9e132920f0ae SHA-1: d398024385397649806716f7bc8341768c1dc55e SHA-256: 824bcea21df66ec0936a76b5a459001f2b5bd570d118b656bd1bc383ae3d061b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and link farm heuristics, indicating its primary purpose is to redirect users to potentially malicious websites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, possibly leveraging JavaScript for exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 https://smidgel.ru/uplcv?utm_term=how+to+draw+a+caterpillar
    • https://tinhhoaxanh.vn/userfiles/file/kudifebuvod.pdf
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/fu414ik6e8r4rmbo2iosbb0955/74630522721.pdf
    • https://sporyolu.com/resimler/files/429701905.pdf
    • http://c-amc.com/upload/files/nelumivoxafijok.pdf
    • http://80tner.netsociality.com/upload/files/dekoxebekemivubuke.pdf
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613021da9b7af---70556382088.pdf
    • http://nadafashionbelt.com/Uploads/file/61191157821.pdf
    • http://irvinenott.co.uk/ckfinder/userfiles/files/71216201071.pdf
    • http://zjqzzx.com/uploadfile/file/2021090106261673499.pdf
    • http://massvt.sk/editor_uploads/system/files/76131168278.pdf
    • https://tranhtreo.com/images/ckeditor/files/10606746376.pdf
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/pogosi.pdf
    • http://alvitraders.com/files/wukujotegulezub.pdf
    • http://ryanoomen.nl/uploadimages/files/7309651437.pdf
    • http://goforthegreengolfpools.com/userfiles/file/23149590682.pdf
    • http://rainhouse.kr/data/editor/file/1855676940613c3781eb56e.pdf
    • https://beta.nhatthiengroup.com/files/uploaded/files/62710013670.pdf
    • https://www.tyrtaios.gr/ckfinder/userfiles/files/xodepijibogeritelipevake.pdf
    • http://sabaispa.net/userfiles/file/69717938428.pdf
    • http://jumpinfit.it/userfiles/files/83261465999.pdf
    • http://aydinservis.com/ckfinder/userfiles/files/22299685283.pdf
    • http://progetec.org/userfiles/files/55597607540.pdf
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613637a3efdd8---69691953976.pdf
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/44dccf75787b7583ce0da4c5f000a1ef/48835268311.pdf
    • http://www.weilandensemble.nl/ckfinder/userfiles/files/tipip.pdf
    • http://cuspsurgeons.com/userfiles/file/binevoxifowurasuna.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_off0000cf34.bin
cb65c5747edd4b671037111e09064d49e7bb923f1545597017521d658bbccce4
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF34 10312 bytes
font_01_sfnt_off0000e684.bin
9ff7e20a7859d455e9e32f734d85f66d2ae6e281bceba543213f84e60e722c2f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE684 17772 bytes
font_02_sfnt_off000114da.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x114DA 16792 bytes