Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a1b416d2089f1c6…

MALICIOUS

PDF

71.9 KB Created: 2021-10-02 16:51:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 5fb72b94f4fa75e34b914e7f248e128b SHA-1: cd4fda88d683ab9de74941ffc42f3063876c8b11 SHA-256: 0a1b416d2089f1c6df4d81e5cb579afc7fbb58e88b221dc1a09683bd03f1cdc1
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external domains, suggesting a phishing or malware distribution scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this by indicating the PDF acts as a link farm on disposable hosting, likely to obscure the true destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://medvor.ru/uplcv?utm_term=12th+new+syllabus+commerce+book+pdf PDF link annotation
    • http://optometrystaprzemysl.pl/userfiles/file/lojutadefoxigarozudim.pdfIn PDF document text
    • https://odontologosmalca.com/images/userfiles/file/bofal.pdfIn PDF document text
    • http://smartraoptics.com/fck_filemanager_upload/file/98282615557.pdfIn PDF document text
    • http://hftyby.com/upload_fck/file/2021-9-2/20210902044228928986.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/vukenepivubu.pdfIn PDF document text
    • http://onnetsolution.in/userfiles/file/xomowerukesuze.pdfIn PDF document text
    • https://mimpishio2.net/contents/files/xurexapabisibol.pdfIn PDF document text
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/gopitajelipibem.pdfIn PDF document text
    • http://benhvienlaptop.biz/userfiles/file/vafamivikojetatiro.pdfIn PDF document text
    • http://studiomanzella.com/userfiles/files/nutewej.pdfIn PDF document text
    • https://rsun.pro/admin/ckfinder/userfiles/files/61507519878.pdfIn PDF document text
    • http://unixsensor.com/uploads/files/202109270855133138.pdfIn PDF document text
    • http://erh-hu.com/userfiles/file/beloximedemoganoguwopisaf.pdfIn PDF document text
    • https://securitydm.eu/slicice/file/26442721468.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-9-29/20210929073104267818.pdfIn PDF document text
    • https://santchavarabed.in/ckfinder/userfiles/files/sujofix.pdfIn PDF document text
    • https://derya.afmiletisimajansi.info/resimler/files/kubasusivowa.pdfIn PDF document text
    • http://alexdisinfestazioni.com/userfiles/files/63670443732.pdfIn PDF document text
    • http://nuuts.mn/uploads/assets/xazoz.pdfIn PDF document text
    • http://manpukulivermore.com/uploads/files/54611932531.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/85609842481.pdfIn PDF document text
    • http://kondicionery-elektrostal.ru/upload_picture/file/masobubuzireweke.pdfIn PDF document text
    • http://portaldeaquidauana.com.br/ckfinder/userfiles/files/85262970456.pdfIn PDF document text
    • http://derkwoo.com/upload/editor/files/23481315966.pdfIn PDF document text
    • http://nhakhoasaigonkimcuong.com/uploads/images/files/sewovabelesibobiwuja.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_off0000b303.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB303 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB1A 11400 bytes
SHA-256: fd3f36a33a723d67e071d816e98f2934312026eb5b981759f0c5d42a9fccfd65
font_02_sfnt_off0000e5c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C3 17616 bytes
SHA-256: 8e350a9427c5e71008e559816581ec01c7586ad1548625dfc6d598e9c20b833a