Malicious PDF — malware analysis report

Static analysis result for SHA-256 21c7c76e29a69ba4…

MALICIOUS

PDF

83.1 KB Created: 2021-09-23 05:36:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: ed48c78b8468875f8be6b592c84c0682 SHA-1: ba90001a178cca76933cf420fd6f22b68c45dd35 SHA-256: 21c7c76e29a69ba4217be9bf9e306a35b5a3bee65edd1399bd6db37eeea176fc
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites, a common technique for distributing malicious content or conducting phishing attacks. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were extracted, the structure and URL patterns suggest the document is designed to lure users to external, potentially harmful, resources.

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://pp-aqua.com/userfiles/files/5053040284.pdf In PDF document text
    • http://hwayoung.kr/upfile/files/65444318293.pdfIn PDF document text
    • http://tnslib.su/userfiles/files/15225956120.pdfIn PDF document text
    • http://diakmelo.hu/ckfinder/userfiles/files/goforidalofujuvagezawa.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e001879729---luwuxije.pdfIn PDF document text
    • http://trungtamsangloc.vn/uploads/ck_upload/files/pukugefifiru.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/rufifimofofuwatigemi.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/f20mip690oobff5qmvorti9k02/foxupedovifuvowifawow.pdfIn PDF document text
    • https://ichapps.peaceofworld.com/ichapps/ckeditor-ckfinder-integration/uploads/files/65025962464.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/nibogijekifex.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1613b207bb8b0a---zefojudozapiperikid.pdfIn PDF document text
    • http://sicilyontable.it/userfiles/files/dojuxixisafak.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/d7583f6a17765a519bc240776af0de3f/puzotew.pdfIn PDF document text
    • http://polletnv.be/uploads/files/30644240842.pdfIn PDF document text
    • https://yourdentist.ro/app/webroot/files/userfiles/files/gutopisojawilar.pdfIn PDF document text
    • http://cokhilegia.com/upload/files/torojirume.pdfIn PDF document text
    • http://www.lircai.com/web/inline/file/mixutexonujilolu.pdfIn PDF document text
    • http://maristaslardero.es/userfiles/file/bogukomolapobemedadutogeb.pdfIn PDF document text
    • https://webkapper.nl/ckfinder/userfiles/files/56838880782.pdfIn PDF document text
    • http://nanouklid.cz/upload/file/bapopur.pdfIn PDF document text
    • http://saktigroup.in/uploads/vipami.pdfIn PDF document text
    • https://drhuanghair.com/uploads/files/202109150611386698.pdfIn PDF document text
    • http://skulpt.in/admin/uploads/file/guvaposuzejirin.pdfIn PDF document text
    • http://bladensburg.abwingsmd.com/uploads/files/25917668883.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/22140317056.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=fight+night+live+updatesPDF 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_off0000e16c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE16C 10596 bytes
SHA-256: 25995cf5918a254437dc1f3c42633ba65dfda5e7c1a1be64005fe63d9c6a5ee0
font_01_sfnt_off0000f958.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF958 17268 bytes
SHA-256: d883de5fc9d2c5ff75e587d4fb9e4a291eeaf63dea137a1037d485fe949886e6
font_02_sfnt_off00012695.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12695 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1