Malicious PDF — malware analysis report

Static analysis result for SHA-256 543c6b0878dc0be0…

MALICIOUS

PDF

81.8 KB Created: 2021-09-08 17:04:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1de77b45b22301008c014cfb2fc9f425 SHA-1: a804cb79f4d96271b480dfefebb563161c697629 SHA-256: 543c6b0878dc0be041c769b4736123efabe6cc866e99c6152f386b1726d53897
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm that directs users to various domains, including those hosted on compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to lure users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://beta.nhatthiengroup.com/files/uploaded/files/jexivuxodivim.pdf In PDF document text
    • http://quangcaosms.org/media/ftp/file/56659217754.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/c23aae0d61d8299213ffd070c02d2652/73474667037.pdfIn PDF document text
    • http://saothienemb.com/uploads/images/files/bulenodamu.pdfIn PDF document text
    • http://moyamoya.center/images/hand_uploaded/files/xovolerepesifumenubadufux.pdfIn PDF document text
    • http://dymenahealthcare.com/upload/fckeditor/file/11623981287.pdfIn PDF document text
    • https://gruppopolidori.com/upload/image/file/vinazu.pdfIn PDF document text
    • http://kurier48.pl/files/userfiles/file/virelip.pdfIn PDF document text
    • https://samuelben-horin.com/userfiles/file/jopapevakapavi.pdfIn PDF document text
    • http://fabiocaronearchitetto.com/userfiles/files/96573724821.pdfIn PDF document text
    • https://www.frontieregypt.com/sites/all/libraries/ckfinder/userfiles/files/34864428240.pdfIn PDF document text
    • http://medob.org/SITE/files/editor/file/67652947700.pdfIn PDF document text
    • https://www.tzounakos-insurance.gr/ckfinder/userfiles/files/49134046197.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/28453434353.pdfIn PDF document text
    • https://congnghieptauthuyvietnam.vn/upload/files/27127852647.pdfIn PDF document text
    • http://celesteandtorsten.wedding/images/file/97559468555.pdfIn PDF document text
    • http://thuexe7cho.vn/upload/files/57947175346.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea0819c7c0---23832834174.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/1543308334.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136e56e112d6---43081563161.pdfIn PDF document text
    • https://yenhuy.vn/upload/files/66043604785.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/99058800484.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/q4t936gk4b9crskbgcfgdr6uc0/gasobifezulomutup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=la+neurulation+embryonnaire+pdfPDF 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_off0000d78d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD78D 19188 bytes
SHA-256: 88843be977ff33c60237ec034dc1c13326b64ba011f0f5f9ab1fd7e7d548d44d
font_01_sfnt_off000107a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FB7 10804 bytes
SHA-256: 5c58f99ff4fbf44e3f9a3a2eaa746d328d68758af92fae9a97be73c6b5eaba33