Malicious PDF — malware analysis report

Static analysis result for SHA-256 a787eb684c2672ae…

MALICIOUS

PDF

83.1 KB Created: 2021-09-11 19:24:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: dda77fddb89fa9a7164962a492ee05da SHA-1: 1776432f34b105ed9120834700f27b4f68d6968e SHA-256: a787eb684c2672ae5f95227af7b307824281e759ac3845f39f642b226d7477d6
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous domains, many of which appear to be disposable or compromised, suggesting an attempt to distribute further malicious content. The ML classifier strongly indicates malicious intent. No scripts were extracted, but the structure and URL patterns are consistent with a downloader or redirector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://lidaoxc.com/upload/files/6082524079.pdf In PDF document text
    • http://libertyquad72.fr/userfiles/file/41187665407.pdfIn PDF document text
    • http://nanouklid.cz/upload/file/mufate.pdfIn PDF document text
    • https://www.channeloflove.com/ckfinder/userfiles/files/banonik.pdfIn PDF document text
    • http://studiotecnicobonoli.com/userfiles/files/78781720868.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361c1c62f29---gawemewobum.pdfIn PDF document text
    • http://intertribo.sk/files/laxulovomowesokag.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/821845252.pdfIn PDF document text
    • http://fese.in/ienupdimages/images/files/53482428417.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613438cc982c8---gasogudikelumopoxof.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/46968975762.pdfIn PDF document text
    • https://mrdak.cc/uploadfile/files/29444756854.pdfIn PDF document text
    • https://santaclara.com/wysiwygfiles/file/xixoxadadogivugozunupave.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/200bd06199eeae3c3d84c231777bdd5e/36218650082.pdfIn PDF document text
    • http://sourceandsecure.com/uploads/userfiles/file/78805400406.pdfIn PDF document text
    • http://rentaruedas.com/files/others/76778581678.pdfIn PDF document text
    • http://argyleliquidations.com/userfiles/files/maxubufowur.pdfIn PDF document text
    • https://kolkatanagariksammelan.org/ckfinder/userfiles/files/ponatinugezetabizubiselub.pdfIn PDF document text
    • http://studioscoponi.eu/userfiles/files/57830639846.pdfIn PDF document text
    • http://rent2day.ca/ci2/userfiles/files/97999430752.pdfIn PDF document text
    • https://mekongtransport.com/upload/userfiles/files/87950187466.pdfIn PDF document text
    • https://goooinggroup.com/userfiles/files/20210903_180946.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/59891685629.pdfIn PDF document text
    • http://kondicionery-lubertsy.ru/upload_picture/file/lefotawajad.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=real+cricket+20+apk+downloadPDF 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_off0000ddbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDBF 18396 bytes
SHA-256: 7f5c7af2801cbc0d9e34b0635b6046b11232e6e3724e0cf49765f664f49216eb
font_01_sfnt_off00010db6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB6 10804 bytes
SHA-256: 01994b1c0b7e9c6322350ae0518a453bc9bd3d2f08b0b09ad026e4277e2adf41
font_02_sfnt_off000126d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1