Malicious PDF — malware analysis report

Static analysis result for SHA-256 7e9cb8c9ebf955b2…

MALICIOUS

PDF

81.5 KB Created: 2021-09-13 00:21:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9246c5a25a70d196798242857e233dc4 SHA-1: e6c21c39e529fa66ed50f3d95fbd6ec0e864132a SHA-256: 7e9cb8c9ebf955b24dc4903a37e714f556d29a7a47d2bb9062b9451a143c4318
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, characteristic of a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://k2plusinterior.com/userfiles/74155213332.pdf In PDF document text
    • http://cortabellanews.com/userimages/7228426839.pdfIn PDF document text
    • https://mvpartners.be/images/uploadedimages/file/gonavamilibeguvugasadadu.pdfIn PDF document text
    • https://aspirans.com/files/file/fosazanajabijoreme.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d28d31eb0---87296832279.pdfIn PDF document text
    • https://posetili.ru/userfiles/file/pugisasarovepolir.pdfIn PDF document text
    • https://arrad.ch/modules/ck/ckfinder/userfiles/files/73531777270.pdfIn PDF document text
    • http://plechotice.sk/tmp/file/23177126397.pdfIn PDF document text
    • http://xn--80aab8aioy.xn--p1ai/userfiles/file/dufap.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161310de994798---wofolowat.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613190f1a117c---gadidilabuzuxawiposim.pdfIn PDF document text
    • http://behtarinekhodetbash.com/files/files/nafofezidiri.pdfIn PDF document text
    • https://amigo-shop.105h.net/upload/files/59639029111.pdfIn PDF document text
    • http://aquamedia.cn/ckfinder/userfiles/files/38050950630.pdfIn PDF document text
    • http://aspbae.org/userfiles/file/22784598651.pdfIn PDF document text
    • https://y3stwk65l-mn9.com/contents/files/numurikewozan.pdfIn PDF document text
    • https://client-sms.com/ckfinder/userfiles/files/48872524885.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca00d3da02---8393736632.pdfIn PDF document text
    • http://www.octopus-quatuorvocal.com/ckfinder/userfiles/files/43315402280.pdfIn PDF document text
    • http://racecross.com/upload/edito_fckeditor/file/munisokobisasusa.pdfIn PDF document text
    • http://gewald.ru/content/Files/30260539300.pdfIn PDF document text
    • https://deltagroup.bg/uploads/file/60761046702.pdfIn PDF document text
    • http://laserinnsbruck.com/static/kevirujadelokijasub.pdfIn PDF document text
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/62602300363.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=set+voice+recording+as+ringtone+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_off0000dbb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBB0 17152 bytes
SHA-256: 88113709e859a82edf4a191469e63e8aae3a190cbc5d0cf17832d36d059cee6f
font_01_sfnt_off00010822.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10822 10640 bytes
SHA-256: 3c39a06702950f5401f5b76d3c3fea860ed794dfe683e94a24f448be20bb7e4d
font_02_sfnt_off0001206d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1206D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1