Malicious PDF — malware analysis report

Static analysis result for SHA-256 f838b8d9e3a07c18…

MALICIOUS

PDF

84.4 KB Created: 2021-06-25 12:13:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: d5b61cbafc9bac7fc02dc472c59e832c SHA-1: f1de75d524bea2b3af04f5ff29b3fa426e5e9eac SHA-256: f838b8d9e3a07c18cb6b78b7371e9e27d5b1e7e2e07b208db3930c82fc7fbb7c
196 Risk Score

Malware Insights

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

This PDF document is flagged as malicious by ML classifiers and ClamAV, exhibiting characteristics of a phishing lure. The heuristic 'SE_REMOTE_SUPPORT_LURE' indicates the document likely instructs the user to install remote-support software, a common tactic for gaining unauthorized access. Numerous embedded URLs point to compromised websites and disposable hosting, suggesting a distribution network for malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Remote-support tool lure high SE_REMOTE_SUPPORT_LURE
    Document instructs the user to install, open, or connect with a remote-support tool such as AnyDesk, TeamViewer, Quick Assist, or ScreenConnect — high-risk in an unsolicited document
  • 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://cructi.ru/uplcv?utm_term=moca+dementia+test+pdf PDF link annotation
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4da1f5ba9e---sinoxivaja.pdfIn PDF document text
    • http://zentrumok.com/userfile/files/97244274191.pdfIn PDF document text
    • http://hanlacsclub.com/ckupload/files/7489166783.pdfIn PDF document text
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/64815e44390ed2bf5a0085cd31c10466/83935541415.pdfIn PDF document text
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/8a78ed25da041a37a4b2b418fc66054c/18905568671.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca51133f37---77442250229.pdfIn PDF document text
    • http://beamstraffic.ae/amb/userfiles/file/74746664496.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/9926976600.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/677b503c6fbdc651e4bed3659c3ea5eb/nedurokinilagudoxas.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160baf5674161e---femalamunamoji.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/197554e87cf3828874cef089f7967d60/70694646473.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d8b2351828---61312571459.pdfIn PDF document text
    • http://kirilmazbardak.com/userfiles/file/ripozunanesewu.pdfIn PDF document text
    • https://lensprovn.com/ckfinder/userfiles/files/benudunavizozorifu.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_off0000e743.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE743 10628 bytes
SHA-256: f31b82dbefe798961fd63cdab38d259d6e6af8355d8a87c6415aef96ea033449
font_01_sfnt_off0000ff92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF92 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117A4 16844 bytes
SHA-256: a47f87f58594dfeae2b115cc9cd830516c81de342f5213f769552138626f1e68