Malicious PDF — malware analysis report

Static analysis result for SHA-256 23cb1b7c0a3b6640…

MALICIOUS

PDF

76.0 KB Created: 2021-09-23 02:57:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 81278333067dfde3fb5bf51f48018511 SHA-1: 622de783d0f382d98e3e8cfff651a248ed561584 SHA-256: 23cb1b7c0a3b664057997d84a77ee7b75227c41567b69a7bbd47f30996f6b5e3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document's purpose is to host numerous links on disposable domains, a common tactic for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://88cpap.com/userfiles/files/pokukarosirugizafazuda.pdf In PDF document text
    • https://postelezmasivu-praha.cz/ckfinder/userfiles/files/15053744981.pdfIn PDF document text
    • http://swhwsolution.it/ckeditor-ckfinder-integration/uploads/files/17029037960.pdfIn PDF document text
    • https://fanaf.com/article_ressources/file/vikarijomepifurabafibiro.pdfIn PDF document text
    • https://ccs-corporation.com/ckfinder/userfiles/files/85777266255.pdfIn PDF document text
    • http://dochoiotovn.com/uploads/userfiles/file/68853981980.pdfIn PDF document text
    • http://satisfytech.com/ck/upload/files/kovegimimajotezejamowimis.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/53008310070.pdfIn PDF document text
    • http://uhy-th.com/image/upload/files/zodoligaditufojig.pdfIn PDF document text
    • http://como.gattinonimondodivacanze.it/themes/userfiles/files/tigexupowamukenolazetatun.pdfIn PDF document text
    • http://houtackers.nl/userfiles/file/9252624864.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/161403c29bf7e0---vefomip.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/dokubujazakupijifow.pdfIn PDF document text
    • https://rendszergazda-cegeknek.hu/ckfinder/userfiles/files/bafewabiwiti.pdfIn PDF document text
    • http://kortennis.co.kr/B/ck/ckfinder/userfiles/files/vobipakeveduxuwomigijid.pdfIn PDF document text
    • http://bikipvuikhoedep.com/app/webroot/files/editor_upload/files/84956557799.pdfIn PDF document text
    • http://olgapolyakova.com/files/files/69953272578.pdfIn PDF document text
    • https://corpus.bg/files/fck/file/wetazabewatewizitufotamef.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161456282a5165---gisapazunajitemazunaju.pdfIn PDF document text
    • https://doanandieuduong295doson.vn/namthuan/images/news/files/vinenegenuvi.pdfIn PDF document text
    • http://winterwonderlandzundert.nl/uploadimages/files/vabawekofutibidezigulazi.pdfIn PDF document text
    • http://ekotop.eu/userfiles/file/54870136045.pdfIn PDF document text
    • http://boissee.fr/userfiles/file/xukonixujumezavalapinabax.pdfIn PDF document text
    • http://firsttimehomebuyerstudy.com/images/file/81627624868.pdfIn PDF document text
    • http://hflbdq.com/uploads/file/010755517624.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=maze+runner+3+ytsPDF 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_off0000bf8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF8C 10280 bytes
SHA-256: 90778cdf20fe511c2e7036a205e7464da9599e770f5c18a3baa2970468ecdb31
font_01_sfnt_off0000d6ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6EC 19860 bytes
SHA-256: d124d2ac48e499e10e4db6ca932e4360f05163b95edad3cf745cc7899a8c9904
font_02_sfnt_off00010a9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1