Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8163b4f36b02208…

MALICIOUS

PDF

85.1 KB Created: 2021-10-06 01:08:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6cc96daa6844d4db2dfa87a43f12d101 SHA-1: 1169d6e0658d3ea58517581fc668dcba63ae504e SHA-256: f8163b4f36b02208a7f854423eb5a23d5a57b3278dab3d1b11211a9ff30e4e37
114 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript, indicating an attempt to execute code upon opening. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' suggests the document's purpose is to trick the user into providing a password for a separate archive, a common tactic for bypassing gateway security. The numerous external URLs, many pointing to PDF files on disposable domains, further support the idea of a downloader or dropper mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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 http://ilkyoukais.com/Images/Media/files/lopakevipijik.pdf In PDF document text
    • http://mackyz7automotive.com/js/upload/files/xakiwidozofefigubujifiri.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/09/202109141414272760.pdfIn PDF document text
    • https://hongdung.vn/ckeditor/images/files/40880202319.pdfIn PDF document text
    • http://agama-rc.com/upload/files/64375005011.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/94500690866.pdfIn PDF document text
    • http://vivaibonomo.it/userfiles/files/gagokezemexujafeto.pdfIn PDF document text
    • http://arserwood.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210905155051157705utev76.pdfIn PDF document text
    • https://bravo-hk.com/userfiles/file/42877058663.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/65933568940.pdfIn PDF document text
    • http://cukiernia.eu/upload/files/5680748412.pdfIn PDF document text
    • https://benmoonpharma.com/userfiles/file/80747342469.pdfIn PDF document text
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/faxajarojagimifowaxef.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161496319a7a7f---turuwaludapalodapumime.pdfIn PDF document text
    • http://knuhpharm.kr/userfiles/file/20210907042732.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/11890834032.pdfIn PDF document text
    • http://www.fred-robin.com/ckfinder/userfiles/files/60943559638.pdfIn PDF document text
    • https://egokituz.org/files/galeria/files/loralukovinutorujikepa.pdfIn PDF document text
    • http://eventologia.com/userfiles/files/vozipokuxugilul.pdfIn PDF document text
    • http://yanartextil.com/firma/files/wirolarinimo.pdfIn PDF document text
    • https://kovtec.pl/eurostyl/photos/file/37245104272.pdfIn PDF document text
    • https://bayihoki99.com/contents/files/49115963545.pdfIn PDF document text
    • http://zbigniewrodak.pl/galeria/file/luzawomaladoguxosuge.pdfIn PDF document text
    • http://korea-labels.com/ckfinder/userfiles/files/jitefamaxubuli.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109031637115886.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16140e37c33dc6---37127944920.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=those+who+save+us+book+reviewPDF 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_off0000e5ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AE 19148 bytes
SHA-256: 9d82a02891be299cf2022c9bd4a1d2690ca7ce522b370ef59870d18d9909efef
font_01_sfnt_off00011739.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11739 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F50 10404 bytes
SHA-256: 04d553fd7eeee7f893d044c7e030380ac28a75a4522e62e926f33e8f84766ae5