Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a3644e709b6eadb…

MALICIOUS

PDF

77.4 KB Created: 2021-09-13 01:12:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4cfdc366d588f90bf3d07978abce286e SHA-1: 8a0ad732f8287fcbaf599a8543ca8c5597c621e8 SHA-256: 4a3644e709b6eadb21223c82dfb34bb202122df6bd0046a425dc8f106a68e48e
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple disposable hosts, a common tactic for distributing malware. The 'SE_PASSWORD_ARCHIVE_LURE' heuristic indicates the document likely instructs the user to download a password-protected archive, a method to bypass gateway scanning. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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
  • 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
  • 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 http://udmvdpo.ru/images/files/siromamugodag.pdf In PDF document text
    • http://monarchiaerembolt.hu/tmp/xaradijiza.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/35758037502.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/2d959832325ed081f771696c81ba7e25/56434195873.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/25481068131.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/20282439820.pdfIn PDF document text
    • http://rld-carbon.ru/file/nafejatamizidimujabupubu.pdfIn PDF document text
    • http://ldksolar-officialliquidation.com/userfiles/files/lojak.pdfIn PDF document text
    • http://geredekombiservisi.com/userfiles/file/wixubipefanulanobepas.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/20924891848.pdfIn PDF document text
    • https://ccaquebec.com/userupload/files/49256900816.pdfIn PDF document text
    • https://fminterativa.net/cms/plugins/ckfinder/userfiles/files/47549401795.pdfIn PDF document text
    • http://monticellotownship.org/userfiles/file/sadurebejelejef.pdfIn PDF document text
    • http://hrampetraipavlavosstanovlenie.ru/content/images/user/file/penazutijusenoxoje.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc0772ebd6---6782620952.pdfIn PDF document text
    • http://comlark.ru/userfiles/files/42908384843.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e47e6876ee---jufubewojotozotikexur.pdfIn PDF document text
    • http://radiopoint.cz/userfiles/file/saregakijozatituxijo.pdfIn PDF document text
    • http://vstarmp.cn/upload/files/20210909_121127.pdfIn PDF document text
    • https://fitness-sport.it/userfiles/file/70202451056.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=recover+android+pattern+lockPDF 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_off0000cb30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB30 10544 bytes
SHA-256: 3af162ec17efd9667ac517b9463a0b5d064a2d6a671c935103207ada8909c1f1
font_01_sfnt_off0000e352.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE352 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB64 17072 bytes
SHA-256: 4fdfb10c1ddf86b014c089947c971a3abf7e92580bbf823f0751287630df7d1a