Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb54523a00252348…

MALICIOUS

PDF

68.5 KB Created: 2021-09-23 17:07:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ca47ac1e74165e5e2c5bed438c44db37 SHA-1: cf0c1675c0df7633b0dca2cf1738692cae7e99a7 SHA-256: bb54523a002523485085e4c9088d157889404fc29b847dd5521c0ad88931efd8
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is identified as an image-only lure, typical for phishing campaigns, aiming to trick users into clicking external links. Multiple heuristics indicate a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or redirect users to phishing sites. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 68 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://nieruchomoscikomercyjne.co/files/file/76698981838.pdf In PDF document text
    • http://vektor28.ru/userfiles/file/zusuvubawum.pdfIn PDF document text
    • http://hamyarsanatco.com/ckfinder/userfiles/files/faxarakanigadiwalufibapun.pdfIn PDF document text
    • http://oshcongregation.com/userfiles/file/pawimategir.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613e74c5e1d7e---xozimawoxipebol.pdfIn PDF document text
    • http://decoworld.in/dayafter/uploadimages/newsimages/file/jefuxamaxirera.pdfIn PDF document text
    • http://ride-on-earth.com/images/blog/file/82951820815.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/53973605550.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/99080315151.pdfIn PDF document text
    • http://cungcapbaoduongcuanhatban.com/upload/files/nirebumivagupeput.pdfIn PDF document text
    • http://bixenony.com/userfiles/files/68957081735.pdfIn PDF document text
    • http://mea-travel.pl/userfiles/file/rufire.pdfIn PDF document text
    • https://aldaserwis.pl/ckfinder/userfiles/files/kelilesedazubifirulanidev.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/wivilapokuzise.pdfIn PDF document text
    • http://vizcsap.hu/files/file/39192363650.pdfIn PDF document text
    • http://manegedebuitenwijck.nl/uploads/file/82664948932.pdfIn PDF document text
    • http://asclyziarskyklub.sk/userfiles/file/55874728228.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/3m23r03k77kp7f7uuf0q39bq73/fatiwapipagufavowo.pdfIn PDF document text
    • http://le383.com/uploads/files/85691896943.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d609b49f4e---56996500011.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/luzadukut.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327e8135417---69426848442.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/vaxerikimabubupafabozesa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=how+to+download+free+films+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_off0000b11e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB11E 14048 bytes
SHA-256: fd91e996066910d5e8ca3b4a47768550aa1811c77e2e64d0c23a1968a5c5d14a
font_01_sfnt_off0000d406.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD406 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC1D 10592 bytes
SHA-256: 3967510fb454aefdd1daa3e0b0ce65f5e774a9266ee8d985ed22d02a5e702695