Malicious PDF — malware analysis report

Static analysis result for SHA-256 31fc9d0fcc0fc695…

MALICIOUS

PDF

76.2 KB Created: 2021-09-28 07:47:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: f01f8655594d291a17942e4dbd463061 SHA-1: 65fff1f814e7ce2b706f3b39da069d4717f0977c SHA-256: 31fc9d0fcc0fc69591cb3f6f999f2a6cbf53e6f647920e7ea2d80542610b5961
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. Although no scripts were explicitly extracted, the PDF structure and heuristic firings indicate it's designed to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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://windmill-bv.com/userfiles/files/gilixujitijovomexenazi.pdf In PDF document text
    • https://promptcorporate.com/ckeditor/ckfinder/userfiles/files/lekurolawobisid.pdfIn PDF document text
    • http://irvine.songhakbbq.com/uploads/files/4175592951.pdfIn PDF document text
    • http://prttour.ca/FileData/ckfinder/files/20210925_D5C9D2AFA8E3BBA9.pdfIn PDF document text
    • https://wangwangcamp.com/uploads/files/202109221054246228.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/niwasusuge.pdfIn PDF document text
    • https://lochoanggia.com/upload/files/7351364161.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/3sitembi3uk24345lol7m9hh31/xixem.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16149420787558---puwawali.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/61180548101.pdfIn PDF document text
    • https://gobelsprofil.com/upload/files/70200705254.pdfIn PDF document text
    • http://ciba.lv/uploaded/file/lawikogijilitev.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/8229e7279076fad4c3f11aedd199827d/ziwonuwabijunerasigovo.pdfIn PDF document text
    • http://benly-carson.com/product/files/rexuwivob.pdfIn PDF document text
    • http://neza.cz/UserFiles/File/bopef.pdfIn PDF document text
    • https://eletvital.hu/uploads/files/5687345362.pdfIn PDF document text
    • http://parateam.cz/file/fabujega.pdfIn PDF document text
    • https://optimustelecoms.com/ckfinder/userfiles/files/54550008333.pdfIn PDF document text
    • https://smgbid.com/ckfinder_userfiles/files/xukila.pdfIn PDF document text
    • https://mertlakustika.cz/images/pages/file/43183894196.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/11400641590.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16151b6eb1f865---45369339727.pdfIn PDF document text
    • https://sledovani2.gpshlidac.cz/www/userfiles/files/fopag.pdfIn PDF document text
    • http://hotelalbicia.com/userfiles/file/nirisadijawusibowavuber.pdfIn PDF document text
    • http://airzo.net/userData/board/file/gagetufareg.pdfIn PDF document text
    • http://gardenofsound.com/userfiles/files/36100533166.pdfIn PDF document text
    • https://datawire.gr/files/files/gorojojebawaxip.pdfIn PDF document text
    • https://estduquebec.com/scripts/php/xenocode/lib/ckfinder/userfiles/files/rixuvukoxitigumi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=second+profile+androidPDF 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_off0000c01d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC01D 19688 bytes
SHA-256: 6ce1b30a85478188f745de5702c8e955d8b2e0d6cf9f93b352eba4dd8d7134a9
font_01_sfnt_off0000f2f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F0 10424 bytes
SHA-256: 5c2863d8127dd3c545934583b12b24a2417bd3e054aa965750b18806f916d6bf
font_02_sfnt_off00010aa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AA4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1