Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb28f4165e7be049…

MALICIOUS

PDF

88.4 KB Created: 2021-10-07 13:49:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: bf7ecd02cfbcfb06f8c88a9f6e0f5e73 SHA-1: 3119de622e15d45223c11fc643245a2e4a02b089 SHA-256: fb28f4165e7be0490d4d9d5f338143db59afa3d21de0a27bc94aca16fb89e17d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links, many of which point to disposable hosting or compromised CMS upload storage, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://dreambeauty.kr/upload/fckeditor/file/xenawepigejigupimabujomit.pdf In PDF document text
    • http://www.hebrewforreadingcomprehension.com/content/97145935782.pdfIn PDF document text
    • https://maximatrimony.com/ckfinder/userfiles/files/xavufij.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/wejaxofotasedo.pdfIn PDF document text
    • https://promoform.coreform.it/uploads/file/jeruxubo.pdfIn PDF document text
    • http://drxzhang.com/userfiles/file/30239815073.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/161441d94d04db---68043586259.pdfIn PDF document text
    • http://tsmsaldature.it/userfiles/files/45398057552.pdfIn PDF document text
    • https://tuinvandecruys.be/file/rosodesozejujekub.pdfIn PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/42314946917.pdfIn PDF document text
    • https://vrrc.heart.net.tw/ckfinder/ckfiles/files/84021744103.pdfIn PDF document text
    • http://ottuk-e.org/userData/board/file/58016365579.pdfIn PDF document text
    • https://soudurelausiere.ca/upload/editor/file/nedugamu.pdfIn PDF document text
    • http://konberdbio.com/upload/files/mozinaxizoligefexexi.pdfIn PDF document text
    • https://cylinder96.ru/admin/ckfinder/userfiles/files/44584929649.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/0f87bd6ae652e30970621ec0e0fad558/87685512451.pdfIn PDF document text
    • http://gazosilikatnn.ru/uploads/files/potaloxunog.pdfIn PDF document text
    • https://volgogradexpo.ru/ckfinder/userfiles/files/43318300538.pdfIn PDF document text
    • https://homecareangels.ca/files/files/files/44156495356.pdfIn PDF document text
    • http://vallovin.it/userfiles/files/20811699577.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1615ba0c15099b---muxaxukufogeruvi.pdfIn PDF document text
    • http://oreade-breche.fr/userfiles/file/gajax.pdfIn PDF document text
    • http://nattukoottam.com/userfiles/file/temafowubudarufajaze.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=old+testament+plaguesPDF 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_off0000ef3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF3D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001074f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1074F 20920 bytes
SHA-256: f029840c54bbecdfcdde0059dc467c69f89ec589138506a3c04afb9ecd3efdf0
font_02_sfnt_off00013c24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C24 10548 bytes
SHA-256: 26a97dbd5a17d2dbc6d4c129ba90b4f3c738469b61673286eb61ae59c55a4c09