Malicious PDF — malware analysis report

Static analysis result for SHA-256 b28e38c3ce4fda9c…

MALICIOUS

PDF

81.7 KB Created: 2021-09-10 00:15:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 10c0ef822d086d41f714aa22cc44aa8b SHA-1: 600a43b9eb9dd7b800dd9e0f053b41c7e5aa21cb SHA-256: b28e38c3ce4fda9c6121be32926bd0beaaeb29860587e0e421b2ba56da0ea62f
156 Risk Score

Malware Insights

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

This PDF was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains multiple links to external websites, several of which are hosted on compromised CMS uploads, suggesting a link farm or phishing lure. The document body is unreadable, but the heuristics indicate a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/0d1201b5486e5a3ec762c44f6f72dad9/38481337018.pdf In PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161302d204d777---46350097226.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/31964773948.pdfIn PDF document text
    • http://geasit.it/userfiles/files/tujawadulugubepimanuju.pdfIn PDF document text
    • https://aneri12.eu/res/file/74080243704.pdfIn PDF document text
    • https://smartmedia.ro/app/webroot/files/userfiles/files/6870317715.pdfIn PDF document text
    • http://hitmet.slektenkaas.com/bilder/file/daxatup.pdfIn PDF document text
    • https://baglab.pl/galeria/file/lowedagodemijojida.pdfIn PDF document text
    • http://sd-admin.fazendapenaazul.com/ckeditor/uploads/files/naxukelutakejunabitez.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109090700041105.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/vekekivipe.pdfIn PDF document text
    • https://ezgoe.com/10005001208290177/ckfinder/userfiles/files/vedofisif.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1630486187.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/movosasoda.pdfIn PDF document text
    • http://pjteam.hu/uploads/52882787197.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613354e132347---gesovijaduzomadefutu.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/tijadeseratokuguwofuwiru.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161317634a947f---47088260591.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613a778e1f1ca---12379065050.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/nolitamujukofunuwowu.pdfIn PDF document text
    • http://hftyby.com/upload_fck/file/2021-9-2/20210902123535997596.pdfIn PDF document text
    • http://www.nagsa.es/ckfinder/userfiles/files/waloma.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=how+to+block+system+updates+on+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_off0000d5ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5CE 11196 bytes
SHA-256: 129594a9d0e8546c76ad08297de50a5717020f14eff90ccb9907637e95cb2fad
font_01_sfnt_off0000efd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E9 18980 bytes
SHA-256: 08488170f94c0b4b532f300ea151f4e8c3116b6c96848dd93f4b0547980e3c58