Malicious PDF — malware analysis report

Static analysis result for SHA-256 51b7869d3f659685…

MALICIOUS

PDF

69.0 KB Created: 2021-09-26 00:03:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 56ca1f96a433ba1f4be3e1493fcfeea5 SHA-1: 14fb4e89dd23acc47cb5c94b33920079c53d9b53 SHA-256: 51b7869d3f659685b7265510545357e7e5464ff3d339a7f0c0f41bfe9e8d0204
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and a link farm pointing to compromised WordPress upload directories, suggesting an attempt to host and distribute malicious files. The ML classifier strongly indicated maliciousness, and the presence of multiple external links on disposable or compromised hosting further supports a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://kozlovka.mebel18.com/uploads/files/42931011017.pdf In PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/161480bf42a8d0---lemumolemarurol.pdfIn PDF document text
    • http://sxsasa.org/images_fck/file/1632554339.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/20198615783.pdfIn PDF document text
    • https://lanjutpt1.com/contents/files/nepelerave.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/welijanakitelamox.pdfIn PDF document text
    • http://driscollandgibson.com/images/edit_images/file/13289943998.pdfIn PDF document text
    • https://regionalhealthprogramsww.com/images/file/62380537776.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135d60c6709f---jorodizuvi.pdfIn PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/voxitonu.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/2021913115097736.pdfIn PDF document text
    • https://www.barefoothoa.com/webroot/js/ckfinder/userfiles/files/3667861580.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/161351e6aa7179---zopaka.pdfIn PDF document text
    • https://ginniglobal.com/uploads/file/loviso.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/fifejukaxepawolesa.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/sobasafan.pdfIn PDF document text
    • https://netiko.fr/img/Data/file/mefuw.pdfIn PDF document text
    • https://alkalacarservice.com/public_html/userfiles/file/pepas.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/4842626654.pdfIn PDF document text
    • http://mixmarketing.vn/upload/fck/file/dedipulutegotukaroja.pdfIn PDF document text
    • http://dfzh.jmdftour.com/fckeditor/userimages/file/jojevem.pdfIn PDF document text
    • https://uleshuzatabc.hu/files/file/78144431763.pdfIn PDF document text
    • http://knshzj.com/CKEdit/upload/files/3970887993.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/gajezogu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+change+time+format+on+android+lock+screenPDF 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_off0000ae03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE03 15388 bytes
SHA-256: e685040d13451ceff68550bcc1c1e2fdcb6bb61636a1ff87f3131e96f8cbeb2c
font_01_sfnt_off0000d497.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD497 11092 bytes
SHA-256: c8449b62952839b71165cba47c308b33d8c3c60f83808d4425295b634040d9d8
font_02_sfnt_off0000ee13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1