Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c2093388cd82d8d…

MALICIOUS

PDF

72.6 KB Created: 2021-09-19 03:45:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9315f1541c1d05e15a9ac3b6f0e6d3d1 SHA-1: ac126539edddcf63c6e3581f7c72e36b2ccc43b0 SHA-256: 8c2093388cd82d8d9442467a7a2df2bb34e0a3ac2f4a05395b38b173f6602d2e
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of external URI links and link farm heuristics suggests the primary purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://chcial.ru/uplcv?utm_term=gangstar+rio+city+apk+download PDF link annotation
    • http://fmi.lu/userfiles/files/15070849964.pdfIn PDF document text
    • http://bigbulkbags.ahmadpackages.com/survey/userfiles/files/rejupibakugijubajeruvinil.pdfIn PDF document text
    • https://tattica.byespresso.com/app/webroot/files/upload/files/fevamitajudukudujoj.pdfIn PDF document text
    • https://kirmatas.com/userfiles/file/56039124655.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/84991157680.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161367750e1423---nasixusadawesulirexo.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/mumapubamosabebekase.pdfIn PDF document text
    • http://derechosenred.org/aym_image/files/36865054427.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/46389805731.pdfIn PDF document text
    • https://traffictkt.com/viking1/uploads/files/gavirixowo.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/tavivufe.pdfIn PDF document text
    • http://kunjipsc.com/uploads/files/32241879140.pdfIn PDF document text
    • http://atya.eu/files/file/ketuxakozinu.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/16132381738a16---fazesujudivukolodisifi.pdfIn PDF document text
    • http://hawaiianhunareiki.it/file/nefedasade.pdfIn PDF document text
    • http://multiflex.ru/userfiles/file/43325643175.pdfIn PDF document text
    • http://ms-beauty.com/ckfinder/userfiles/files/62403249689.pdfIn PDF document text
    • http://serviphony.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/20355509462.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/161303bec52e3a---35878772295.pdfIn PDF document text
    • https://cissud.com/uploads/ck_editor/files/41691184263.pdfIn PDF document text
    • https://onlineadda.organicemall.com/ckfinder/userfiles/files/kexoreninopato.pdfIn PDF document text
    • http://shop-exclusive.cz/userfiles/file/sisul.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_off0000b5d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5D5 10888 bytes
SHA-256: 9e950f01d0a0d48fc670e31c8059c2265ef647bb3cea1aef3532e5917168aedb
font_01_sfnt_off0000cf12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e724.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE724 17644 bytes
SHA-256: 7e061d7a6e032e7e29ccee5058c607702379c38526e25341a863ccf0f85921a9