Malicious PDF — malware analysis report

Static analysis result for SHA-256 71bb026ca044d0a7…

MALICIOUS

PDF

73.6 KB Created: 2021-09-27 12:29:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 438a1d68eb4981a08d9fbcffaaf81c13 SHA-1: 7202b0c93f9a026ae68acb3e6ed3cbd390dc47be SHA-256: 71bb026ca044d0a74c8fadcf1bc3a7aaa4be3f277b6657cc730b18cff452782d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://krisoc.ru/uplcv?utm_term=download+manual+camera+dslr+camera+professional PDF link annotation
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/49899812305.pdfIn PDF document text
    • http://girc.ncue.edu.tw/ckfinder/ckfiles/files/71370559677.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614087ce61846---21141315691.pdfIn PDF document text
    • http://peknanevesta.sk/media/file/86764988790.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/14630773238.pdfIn PDF document text
    • http://inphilong.com/upload/files/gojizuditid.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/3cfa77043957411f1b23cba3f2c1d06c/gogakid.pdfIn PDF document text
    • https://turdv.ru/SITE/files/editor/file/jasubewegewekudawikoma.pdfIn PDF document text
    • https://baoholaodong24.baohohoanglong.com/userfiles/file/janomowabi.pdfIn PDF document text
    • https://www.puskinas.lt/ckfinder/userfiles/files/94234868667.pdfIn PDF document text
    • http://plaschke-partner.com/uploaded/file/12822563358.pdfIn PDF document text
    • https://ryokanclub.com/FileData/ckfinder/files/20210909_14C8CE0D02E1B62E.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/40473453938.pdfIn PDF document text
    • https://pchome.uzai.ca/upload/files/3798518592.pdfIn PDF document text
    • http://golfproradost.cz/webpagebuilder/ckfinder/userfiles/files/xojokisu.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/xekalobupupujiwisu.pdfIn PDF document text
    • http://lecieldesandes.fr/ckfinder/userfiles/files/82061676686.pdfIn PDF document text
    • http://theloanwala.com/userfiles/file/jelipe.pdfIn PDF document text
    • https://kaptenhoki.info/contents/files/36467536567.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161413d0954928---77356123938.pdfIn PDF document text
    • http://parcroyale.hk/userfiles/rupitukemenuloziz.pdfIn PDF document text
    • http://unseretochter.ch/images/file/44450731700.pdfIn PDF document text
    • http://studiolegalebisantis.it/userfiles/files/36046607621.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/53009940684.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_off0000b645.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB645 18884 bytes
SHA-256: 6afb4d15aa9989849eaf85d68a564c23b52ce7d8ec8343073da4d0f33e267d99
font_01_sfnt_off0000e78c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78C 10872 bytes
SHA-256: 1d08206e4e6fedaac2e839cdd08bb8d71ecf9d7b05d67ee1e815db4e2ca054d6
font_02_sfnt_off000100a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1