Malicious PDF — malware analysis report

Static analysis result for SHA-256 b12638fef4d097c3…

MALICIOUS

PDF

86.0 KB Created: 2021-06-25 14:02:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5ebf25f31cc05fc3978917ccfc16035e SHA-1: dbdcf36d3437ff0626c4642877330806969e706a SHA-256: b12638fef4d097c31df30b9086c17fe415cca327b39f6e9440a11a43a5a90550
164 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress upload directories, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to distribute further payloads or conduct phishing. No scripts were extracted, but the structure and URL findings are sufficient for a high-confidence assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b524d709942---93569401875.pdf
    • http://derma-dts.de/files/file/34553190069.pdf
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16071aa667d503---temanikekiwefese.pdf
    • http://softwarefactory.nl/images/file/juloko.pdf
    • https://hkbca.org/UploadFiles/file/20210604173718158.pdf
    • http://learnazia.com/fck/imagesfile/58890765471.pdf
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/10134372628.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/40d3901dcc69d364cad53f0648765443/wulixejibenafirurujomexi.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf262b3a13---68271425969.pdf
    • http://auto-spec.ca/fck/file/88382810643.pdf
    • https://www.alapan.org/fckimages/file/lefozozotu.pdf
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160988424e835d---furukonegetu.pdf
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609854f288740---39260272170.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/02fruqqplhp9eals3t64br2kl3/ronirili.pdf
    • http://sea-cruise.ru/ckfinder/userfiles/files/wugus.pdf
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c105d28e948---tojewuw.pdf
    • https://abofahed.com/userfiles/file/15131640452.pdf
    • http://stardentalcare.org/userfiles/file/31855608906.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=tv+trivia+questions+and+answers+2011
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb7c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB7C 16792 bytes
font_01_sfnt_off0001038e.bin
29445529eaf9af247ed2342f71a17296638bc64957193a5f21b3c23d7e3df557
pdf-font-stream PDF embedded font (sfnt) at offset 0x1038E 17596 bytes
font_02_sfnt_off000131b6.bin
5d2dcfa26cba7794b04905ce6581d28cbd09a3c41d52d9f9532267ec84cb0de2
pdf-font-stream PDF embedded font (sfnt) at offset 0x131B6 10848 bytes