Malicious PDF — malware analysis report

Static analysis result for SHA-256 df331533191e33a6…

MALICIOUS

PDF

84.2 KB Created: 2021-09-19 23:08:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 10240aab62e95872577596b82e6554ab SHA-1: a6f9b13cd78df43ee131af67bb486c8f1b3a343b SHA-256: df331533191e33a6668a3e4c20738f89f326c90c260fdea4610a93928bb200b1
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier strongly indicated maliciousness, and numerous heuristics identified the PDF as a link farm on disposable hosting. The embedded URLs, such as 'https://crysiq.ru/uplcv?utm_term=how+to+use+your+phone+as+a+speaker', suggest a phishing or content-luring scheme. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 4

  • 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 https://crysiq.ru/uplcv?utm_term=how+to+use+your+phone+as+a+speaker PDF link annotation
    • http://sushigonewildtogo.com/uploads/files/jujepinumibopigofukob.pdfIn PDF document text
    • http://www.sas.edu.mn/ckfinder/userfiles/files/73299374709.pdfIn PDF document text
    • http://autoscuolepintozzi.it/userfiles/files/velizej.pdfIn PDF document text
    • http://dtpokebar.com/uploads/files/15891341257.pdfIn PDF document text
    • http://7sate.com/filespath/files/20210906044823.pdfIn PDF document text
    • https://cdmsig.com/ckfinder/userfiles/files/52534569972.pdfIn PDF document text
    • https://vietcuongcorp.com/uploads/news/files/gufeginukinukozojanul.pdfIn PDF document text
    • http://hanyuchina.com/upload/files/zefogusilumovo.pdfIn PDF document text
    • http://www.papelerialapiceros.es/ckfinder/userfiles/files/litubidujetuluxovot.pdfIn PDF document text
    • https://repairbase.net/FCKeditor/editor/filemanager/connectors/php/images/file/73129059535.pdfIn PDF document text
    • http://pnktools-th.org/ckfinder/userfiles/files/boresosepukukesum.pdfIn PDF document text
    • https://vico-domrep.com/ckfinder/userfiles/files/39278297081.pdfIn PDF document text
    • https://takipbizde.com/calisma2/files/uploads/1520202119.pdfIn PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/42482123213.pdfIn PDF document text
    • https://giaphutelecom.com/tctt/sites/aaa/file/manexenijakulusatisebap.pdfIn PDF document text
    • http://cdkuys.handysociality.com/upload/files/xakafitivesikovobu.pdfIn PDF document text
    • http://mid-europe-ex.com/images/blog/file/bisigokimitazusuwegigega.pdfIn PDF document text
    • http://proxima-design.cz/files/file/kitazodi.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/16147787476a92---jinuwisufaxuza.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328264052d3---13813048062.pdfIn PDF document text
    • http://felixefontesadvogados.com.br/ckfinder/userfiles/files/tixojapaxekanerivon.pdfIn PDF document text
    • http://eminenceinc.com/userfiles/file/14994786409.pdfIn PDF document text
    • http://rococosofa.com/files/files/92431656884.pdfIn PDF document text
    • https://newcar-rental.com/uploads/files/202109020721103729.pdfIn PDF document text
    • http://3colorjazz.com/fckeditor/userfiles/image/9526600888.pdfIn PDF document text
    • https://ichibaninfotech.com/ckfinder/userfiles/files/5554105792.pdfIn PDF document text
    • 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_off0000e593.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE593 17344 bytes
SHA-256: 84508eb2042045921a8f6f4d0a887ccf0c31f18c54b322805f83b5caf1ed5d7a
font_01_sfnt_off0001127f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1127F 10596 bytes
SHA-256: 57a84870af348ae5672e8551b93e909eef2caaf10e05ea33613bf512504070e6
font_02_sfnt_off00012ac0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1