Malicious PDF — malware analysis report

Static analysis result for SHA-256 caa4690e9789edaa…

MALICIOUS

PDF

86.7 KB Created: 2021-09-08 11:30:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: dcf65bc88ccc4d0982d217ef33e9df67 SHA-1: 9e4e7ae2fc2b4331791d7997c1b3f5783d493062 SHA-256: caa4690e9789edaa8b79c28ee50d4c22dafc451d2143a74f46ca85acfc92e1b8
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with multiple URLs pointing to potentially compromised websites or disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of numerous external URIs and the nature of the detected heuristics strongly indicate a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://zonwering-nederland.nl/ckfinder/userfiles/files/55733318999.pdf In PDF document text
    • http://fxlcd.com/upload/file/72802742135.pdfIn PDF document text
    • https://smartcirclegroup.com/userfiles/file/42576186139.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/8649554293.pdfIn PDF document text
    • https://truck-diagnostic.ru/wp-content/plugins/super-forms/uploads/php/files/18b85ce8afd2e68a5f3188fea861f96a/26224300049.pdfIn PDF document text
    • http://canxetaianhduc.com/images/file/mezonawanugigerekafex.pdfIn PDF document text
    • https://leosservices.com/userfiles/file/76707308613.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608db3709486f---mubifaxupedagenegapo.pdfIn PDF document text
    • https://tmtteks.com/files/fixijakamazivenalowad.pdfIn PDF document text
    • http://mamtomchabahai.com/uploads/files/files/nenosibirumaxowav.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/modopobexuzizileji.pdfIn PDF document text
    • http://drkoopman.nl/cmsimages/file/mimuligino.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa6e8412492---19949515093.pdfIn PDF document text
    • http://jtour.vn/userfiles/file/3363696211.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093d64aca5e0---59400826351.pdfIn PDF document text
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/73978915826.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/37120705996.pdfIn PDF document text
    • https://chambres-hotes-aube-bleue.fr/userfiles/file/77296887855.pdfIn PDF document text
    • http://numismatika-nbkpdy.cz/userfiles/file/sinejidika.pdfIn PDF document text
    • http://bebelino.ru/userfiles/file/77318061332.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/wopirevemifapopezew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=ndps+act+1985+pdf+in+marathiPDF 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_off0000defd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEFD 11124 bytes
SHA-256: edf3994a52c4c033167d3d9bb554b0002638328d94302a138992a2aa63085707
font_01_sfnt_off0000f8db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000110ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110ED 22348 bytes
SHA-256: aa656f330e63c40410ed66205529ea2eae8387c4dff21efd969df6b734bc7d0b