Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a85503fd3952171…

MALICIOUS

PDF

80.1 KB Created: 2021-09-19 11:21:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 49e3a82e989e8d597da98f3dc3d99adf SHA-1: ab1d174a88c57a2841eefc1704715af63107f3cf SHA-256: 4a85503fd39521719357a7d4b062be4267e5700be712479d55e6d695a6c32098
174 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. The presence of external URIs and a link farm suggests an attempt to redirect users to malicious content. Furthermore, the heuristic indicating a security bypass instruction to disable antivirus software strongly supports a malicious phishing or malware delivery scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nomylo.ru/uplcv?utm_term=skate+city+apk+download PDF link annotation
    • http://zjqzzx.com/uploadfile/file/2021091514521473499.pdfIn PDF document text
    • http://wwpokebar.com/uploads/files/janozixamojurubaritum.pdfIn PDF document text
    • https://grnca.org/img/files/files/86253225312.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/57172671f3174577e077cc0bae136059/42289196296.pdfIn PDF document text
    • https://www.liftechforklifts.com.au/application/third_party/ckfinder/userfiles/files/1664834474.pdfIn PDF document text
    • http://nzozkrowodrza.pl/uploads/editor/file/58121832686.pdfIn PDF document text
    • http://tabletopad.com/images/file/xogak.pdfIn PDF document text
    • http://qataminational.com/uploaded_files/userfiles/files/ruligigif.pdfIn PDF document text
    • http://goksirkrupskimlyn.pl/img/upload/files/tikobazev.pdfIn PDF document text
    • http://mcdanielz.eu/files/file/gibosezejabixegewaxefim.pdfIn PDF document text
    • http://theonejsc.com/userfiles/file/xilenumodivekaruwezowora.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/25219319110.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/161449ec53caf6---xizagixokemuvikolopak.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/39954143909.pdfIn PDF document text
    • http://bora.su/ckfinder/userfiles/files/71676694250.pdfIn PDF document text
    • https://vandolderskb.com/images/usr/zesujisezobod.pdfIn PDF document text
    • http://kartywspomnien.pl/uploads/assets/file/bidajugomirela.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/riwumaguzujisipolopifaj.pdfIn PDF document text
    • https://mobilaide.com/upload/editor/file/warowamew.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/risizok.pdfIn PDF document text
    • http://veoguidecostarica.com/ci/userfiles/files/55091915850.pdfIn PDF document text
    • https://terlickodds.cz/www/www/fckphotos/file/70922166607.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/77844434429.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_off0000d305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD305 18196 bytes
SHA-256: df221ac3a86da4c63d2c21c8fdda83521c829522b032b0c9250264771d359482
font_01_sfnt_off000102c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C5 10608 bytes
SHA-256: abcb77d68654b458d857ed75620b6b5786323a0c19609eaa28b5aaf71df652c0
font_02_sfnt_off00011b3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B3C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1