Malicious PDF — malware analysis report

Static analysis result for SHA-256 86dc4df1812ae70f…

MALICIOUS

PDF

78.3 KB Created: 2021-09-14 07:31:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 67f6e9d9fb12c9eb5fcfdfa1bb2f6b72 SHA-1: a1915ab0ba8bb8a26e55e7c768976f8213a97e03 SHA-256: 86dc4df1812ae70f8ed5f63706cf4af92c1013cabae7bf066ec1424bc518c8fd
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous links pointing to potentially compromised websites or disposable hosting, suggesting an attempt to lure users to external malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://brucemayrockinstitute.com/assets/ckfinder/core/connector/php/uploads/files/58186861957.pdf In PDF document text
    • http://kabaretyimpresariat.pl/Upload/file/segoninuvesusozefuselot.pdfIn PDF document text
    • https://nibrasimansch.com/userfiles/files/xamafuj.pdfIn PDF document text
    • https://stradatextiles.com/upload/ckfinder/files/mutiferuduxike.pdfIn PDF document text
    • http://generaltubi.com/container/ckfiles/files/93597530255.pdfIn PDF document text
    • http://idominjazz.com/fckeditor/userfiles/image/kulofaviginidonobafuxi.pdfIn PDF document text
    • http://artediapharma.com/upload/files/67465477206.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/77016706198.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1613b5e1894ab6---9407976207.pdfIn PDF document text
    • http://cuacuontoanthang.com/media/file/87993167812.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16132da867ed7f---nezen.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/98516713037.pdfIn PDF document text
    • https://trexanh.net/upload/files/47037271318.pdfIn PDF document text
    • http://jinsonmetal.com/Upload/file/zonunifofajebakudik.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/1612fef63aa809---88489488627.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/74680281861.pdfIn PDF document text
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/piwixoju.pdfIn PDF document text
    • http://ateliergermain.club/sites/default/files/file/rifenozofavadasewivejek.pdfIn PDF document text
    • http://jjinline.org/file_upload/file/fasowujex.pdfIn PDF document text
    • https://chungcungoaigiao.vnpec.xyz/uploads/files/gazixesukodubaxozedi.pdfIn PDF document text
    • http://1utilaje.ro/mm/file/gasevokaminifi.pdfIn PDF document text
    • https://vjlabor.pitscovn.com/uploads/Upload/files/45181949749.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=the+hunger+games+mockingjay+part+2+streamPDF 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_off0000cdb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDB7 11292 bytes
SHA-256: 03d8f32e3a7efab512cbda37eab4b7f93796e1438fc08ed376b8e3e20af09682
font_01_sfnt_off0000e825.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE825 16852 bytes
SHA-256: 55ca463b5f1a61bf66fcd4bf8a7637b4306fb01b35c6202893d4de4bcf215a43
font_02_sfnt_off000113c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1