Malicious PDF — malware analysis report

Static analysis result for SHA-256 1837bcc74ff51cc4…

MALICIOUS

PDF

81.0 KB Created: 2021-09-03 15:58:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 231e27d6451441105a9206548a0eacfa SHA-1: e230c1571defc4db94d440063950edd376a8c22f SHA-256: 1837bcc74ff51cc4d68e0004028718fe2a4010e925f1074a45a4da3ff0d4ec29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised CMS upload directories, indicating a likely phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is unreadable, but the heuristics and URLs confirm a link farm pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://wabasnb.com/files/fckeditor/file/189845917260d705db662d9.pdf In PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/d6dc5f4f2592bec64796419272823b6a/76070729028.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3a536faad---16783882393.pdfIn PDF document text
    • https://ijpdua.com/contents//files/mimijikogogavi.pdfIn PDF document text
    • https://evergreencans.com/userfiles/file/88561013755.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610b80c38a8bb---48150956418.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/neqrurdq69nivftrf6o629mbv4/35926846189.pdfIn PDF document text
    • https://msiutilities.net/documents/1395645260.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/4e135f6bbc96404d43c8a077d352eb6f/gedoxesidujepizelusutafor.pdfIn PDF document text
    • http://hykylalumni.org/userfiles/68777076016.pdfIn PDF document text
    • https://cristalensi.com/public/File/kazimeka.pdfIn PDF document text
    • https://luatkhangthai.vn/upload/fck/file/zogoxojimevapewem.pdfIn PDF document text
    • http://thetuckerfamilyreunion.com/clients/67950/File/61410691646.pdfIn PDF document text
    • http://michalpavlicek.com/uploaded/file/tovogilebivovabirobeni.pdfIn PDF document text
    • https://www.mii.net/wp-content/plugins/super-forms/uploads/php/files/b8987321663a5e9df94177c2fe7ac3d1/15733940284.pdfIn PDF document text
    • https://hobbes-group.com/upload/files/wiwutejomugoteluvulenedof.pdfIn PDF document text
    • http://isvpro.com/custom/files/fowokefemuxugil.pdfIn PDF document text
    • https://aiwatopup.com/ckfinder/userfiles/files/vudaxopigumapirademiz.pdfIn PDF document text
    • https://basisangka.com/contents/files/powopikexinetorosanu.pdfIn PDF document text
    • http://tydafa.com/dafa/uploadfiles/20210819001731.pdfIn PDF document text
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/bhj8rrqhr4830j86c439a30vg5/62489034585.pdfIn PDF document text
    • http://ongxoanhdpe.vn/upload/files/71515626969.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5015a6a82---bevonuz.pdfIn PDF document text
    • http://jeyadhurgatemple.com/userfiles/file/78551632982.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1611ed89606409---69819759489.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=freebsd+zfs+manual+installPDF 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_off0000d110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD110 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e927.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE927 10672 bytes
SHA-256: f0d68f2b7e8837e07856851a063de5c1dc750344a3e2e6c5d364ac57f2ddc208
font_02_sfnt_off00010193.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10193 20312 bytes
SHA-256: 667ba62e67aece2eb7d93b9a3b54f8f6b9f07c165d7045ecfa23a60eca9ffc3c