Malicious PDF — malware analysis report

Static analysis result for SHA-256 4571bb276621b7fe…

MALICIOUS

PDF

70.3 KB Created: 2021-09-16 02:21:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 0d0c426dd513b15296b848e5d86e4efa SHA-1: 66d72c4bc9a2d9dc587c2fc51d62d5cf2b2aa733 SHA-256: 4571bb276621b7fed03c431c130360be9b590491a06b96b0ba262b4a3c4f17e7
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The primary attack pattern involves luring users through a seemingly innocuous document to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://hongming-eco.com/userfiles/file/71267909805.pdf In PDF document text
    • http://newtrichur.com/userfiles/file/vemamajevur.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/gidewapofulonesat.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/eac469f41eab54f98e402852e4241e20/zadojanulilawujirakojeb.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161382523295a0---zesurodafewarelojeg.pdfIn PDF document text
    • https://nevisnews.com/userfiles/83636860096.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/0adb8e2c6e78a5151ec2be2f14694f94/pesitufitodudibudefekiw.pdfIn PDF document text
    • http://gloteckr.com/upload/editor/file/vefodupufipe.pdfIn PDF document text
    • http://nano-vip.com/ckfinder/userfiles/files/67918519481.pdfIn PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/xisurinuvorizujidazifaw.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161322f2b41d56---13210023776.pdfIn PDF document text
    • http://dogomanhnghia.com/uploads/files/72494965901.pdfIn PDF document text
    • http://flomojapan.com/upload/files/33330960256.pdfIn PDF document text
    • http://wefocusdesign.com/upload/files/matofoxegirifotu.pdfIn PDF document text
    • https://atasuorganiktarim.com/upload/ckfinder/files/39279791952.pdfIn PDF document text
    • http://lahma.pl/_u/userfiles/file/kavujixik.pdfIn PDF document text
    • http://bigcool.net/webroot/img/files/47567145055.pdfIn PDF document text
    • http://pillshop.ru/uimg/files/48216812906.pdfIn PDF document text
    • https://natyabio.com/uploadfiles/18158591998.pdfIn PDF document text
    • http://harekatmemuru.com/images/Media/files/pipevamiruluvevomagu.pdfIn PDF document text
    • http://bojovesporty.cz/userfiles/file/17051948964.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=polytechnic+chemistry+book+pdfPDF link annotation
    • http://pro.ovh.net/~tribuene/images/banque/file/monizezolukepudibetevet.pdfIn PDF document text
    • 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_off0000afae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c7c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7C5 11072 bytes
SHA-256: 4a6ef026948ed443a78133fdde8f05230fff70827914adf6e7a3b7d1892c74d4
font_02_sfnt_off0000e128.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE128 16524 bytes
SHA-256: 1e11d713030edd61305171bc833c5e7eb7728b3e7d34ebd375ad62b3214ac02e