Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cef67f58ee8a790…

MALICIOUS

PDF

82.6 KB Created: 2021-09-23 06:03:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c94307d09689c2df62740281d471c273 SHA-1: 8a8be952b0e776d84bc42022d45a89f16cebc0bf SHA-256: 6cef67f58ee8a790144c062607a2252b5a093f743fca8b608bbdb3a7037943bf
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to compromised CMS upload storage and disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure suggests a lure to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://slhospital.com/upload/fckeditor/file/gomiju.pdf In PDF document text
    • https://rainbowfurnitures.com/files/files/vipajufuludemesex.pdfIn PDF document text
    • https://bunianco.com/other_files/File/60752441576.pdfIn PDF document text
    • http://sfipl.in/userfiles/file/xigevu.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161341364db9ef---19667114413.pdfIn PDF document text
    • http://damosushipleasanthill.com/uploads/files/tigikexifowe.pdfIn PDF document text
    • http://ajarnveerapong.com/UserFiles/file/1634436658.pdfIn PDF document text
    • https://beaszemin.com/files/94378222506.pdfIn PDF document text
    • http://haohanlegend.com/Uploadfiles/files/75890692310.pdfIn PDF document text
    • http://kirilmazbardak.com/userfiles/file/bosajifixuzikonetiwozu.pdfIn PDF document text
    • http://slbreakingnews.com/ckfinder/userfiles/files/32079227616.pdfIn PDF document text
    • https://songhong.info/userfiles/file/jilenexofipifode.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/6562099080.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/bebedeja.pdfIn PDF document text
    • https://chataigne-cevennes.fr/imgs/files/fokomutalijobilo.pdfIn PDF document text
    • http://simonkuehner.de/gfx/userfiles/files/wunefevekojetosa.pdfIn PDF document text
    • http://sdv.sk/userfiles/articles/file/gukudevadiwagaxuleliw.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1614ae23bc12e6---6519668392.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613947f11aaaf---72991232218.pdfIn PDF document text
    • https://nieruchomosciprzetargi.pl/files/file/32863423013.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147b7ec7da4d---duxodagotowaxuku.pdfIn PDF document text
    • http://urbanposthotel.com/admin/ckfinder/userfiles/files/gejawikute.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/18582880582.pdfIn PDF document text
    • https://saigonservices.vn/images/uploads/files/47769184100.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+remove+spam+from+chrome+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_off0000dcff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCFF 10980 bytes
SHA-256: 380a56ba631f94d032747259e15e4968e9a5e976b292a35471a831d0fc01b2c4
font_01_sfnt_off0000f65c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65C 17696 bytes
SHA-256: 2e6097ffdf81f5aa01fdd0c59cf17404892f703338c9002dfed58f9490c92cfa
font_02_sfnt_off00012478.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12478 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1