Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bc3aceb55261d87…

MALICIOUS

PDF

83.7 KB Created: 2021-09-09 14:53:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-23
MD5: 75cb17cebc0fa2de18d6727ffb2d0901 SHA-1: 2a5909b54adad3f675a6821e119f07e7e8080104 SHA-256: 8bc3aceb55261d874dbb1ad2d4183c86bfcb3216b883b77d156cebfee65bd353
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://1-cities.com/blog_images/blog_/file/ronubugavepirosoj.pdf In PDF document text
    • http://smartraoptics.com/fck_filemanager_upload/file/bibapuwiz.pdfIn PDF document text
    • http://i-akparat.kz/ckfinder/userfiles/files/16812731107.pdfIn PDF document text
    • http://minhtoangalaxyhotel.vn/app/webroot/files/ckfinder/files/89481693429.pdfIn PDF document text
    • https://albizy.com/ckfinder/userfiles/files/66648979399.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/gimupafas.pdfIn PDF document text
    • https://bikidi.com/UpFiles/WebEditorFiles/file/52297166749.pdfIn PDF document text
    • https://yp05.com/_UploadFile/Images/file/demomamutaxufideliwolumot.pdfIn PDF document text
    • http://vmkmsz.hu/userfiles/file/lojewikijawufebiguwar.pdfIn PDF document text
    • http://tranindo.com/Uploads/userfiles/files/tibikadudobewemivosojar.pdfIn PDF document text
    • http://velkoobchod-man.eu/ckfinder/userfiles/files/gewulavujajowusega.pdfIn PDF document text
    • http://koreaseowon.com/ckupload/files/fokewokagipux.pdfIn PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/jekoxinod.pdfIn PDF document text
    • http://ediljolli.com/userfiles/files/89511676575.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/9892438dd6d4eda4fda7875799b7d46e/gamefubelexodele.pdfIn PDF document text
    • https://bobecoingatlan.com/uploads/editor/file/26168698603.pdfIn PDF document text
    • https://chulintemple.house-well.com/CKEdit/upload/files/59027208972.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161357ca57b2c1---vebemodijigitutoke.pdfIn PDF document text
    • http://mega.kz/media/upload/files/puzavufanedekozizasidofe.pdfIn PDF document text
    • https://cosonnguyenthanh.vn/webroot/userfiles/files/zuzogobafixefudawidagafi.pdfIn PDF document text
    • http://mediacast.vn/ckeditor/upload/files/devunamegidarilulozu.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16138b8799f06d---32456537643.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/1451016109.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/joran.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=netnaija+nollywood+movies+2020PDF 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_off0000e02a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE02A 18288 bytes
SHA-256: fc5509383de602071ab1069a2c0e82a4e7975aa395691e489e585ddbbe1d3107
font_01_sfnt_off00010fb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000127cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127CD 10924 bytes
SHA-256: ef7996b058248c213e0b0a19a0a4cde9e91171c94e48707948739865481456c9