Malicious PDF — malware analysis report

Static analysis result for SHA-256 25b3a3927a675729…

MALICIOUS

PDF

103.3 KB Created: 2021-08-16 23:55:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 7c4332caa3e096c6665702d09756a4ce SHA-1: 68105affb0c9f6f2b317636d42b99273bd08450d SHA-256: 25b3a3927a6757294a4571e50a95ca5719babaf9d02dbd5b6ac085d50dc0f4f5
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised WordPress upload directories and other disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of a link farm suggests an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://unseretochter.ch/images/file/31064566395.pdf In PDF document text
    • http://sl-light.ru/design/img/upload/file/93521271749.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/535c19bc36f5b21c330dd6673a944b51/65302743795.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/1789e0748293f4415bcdce3afaaa2611/ruketimenipat.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/fa7f869d53680b8ded25f4eeedf2da47/41307243402.pdfIn PDF document text
    • https://imaggu.com/ci/userfiles/files/lotedif.pdfIn PDF document text
    • http://plkorea77.com/ckupload/files/67324753713.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16102db90aedd3---17169667349.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/fdd69a6c8b42d7d1600dd13ed2757d85/wafenusukuzijabimitoduxi.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/3j4670icl47s8eior0qu393qj7/23965479309.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095dbdc68abc---17817837428.pdfIn PDF document text
    • http://nappsa.org/userfiles/file/28853212252.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/964b62bdf337d6682f2eea8226bcda85/94576456998.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/19108191415.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b82c2d76f06---pukukapuke.pdfIn PDF document text
    • http://erpsamik.com/ckfinder/userfiles/files/megutaxu.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e92320b31c8---76427258418.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=windows+server+2012+r2+enterprise+download+iso+64+bit+free+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_off00012d9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D9D 17888 bytes
SHA-256: 34ebb8259682416a94d6ac4ea762ac56ed6305436cd8a961dcccfa4624335bba
font_01_sfnt_off00015cc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15CC3 11316 bytes
SHA-256: e6aa865489ae3b63c7cefb46b6962d2a8cf5d994ac892bce43e4cbd9f475f34d
font_02_sfnt_off0001776d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1776D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1