Malicious PDF — malware analysis report

Static analysis result for SHA-256 359c4b6b3b964c90…

MALICIOUS

PDF

68.4 KB Created: 2021-09-23 22:34:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b31b32594942fdd6dab77dba94be55c4 SHA-1: 953299c453f2f31392240ba7eb50275f34b138f2 SHA-256: 359c4b6b3b964c9053effa13f7f9d6961f83b6972bd55b156302a076f0753100
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file exhibits characteristics of a link farm, with numerous embedded URLs pointing to various domains, some of which are hosted on compromised CMS platforms. The ClamAV detection and the presence of multiple external URIs suggest a malicious intent, likely to lure users to phishing sites or download further malware. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.3748

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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=smb+file+explorer+android PDF link annotation
    • http://sapthagireesyathra.com/userfiles/file/35550885683.pdfIn PDF document text
    • http://broadgatecapital.com/userfiles/file/91627572066.pdfIn PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/ziwexer.pdfIn PDF document text
    • https://vyaspublicschool.com/ckfinder/userfiles/files/30001809242.pdfIn PDF document text
    • https://texasbordervolunteers.org/userfiles/file/wusudowazebuzaxojipazoma.pdfIn PDF document text
    • http://tecsun-moscow.ru/docs/file/42590189085.pdfIn PDF document text
    • http://mamnonsaokhue.vn/app/webroot/files/ckfinder/files/32771334442.pdfIn PDF document text
    • http://ylphs.com/ckfinder/userfiles/files/kiwosifedenowulepuzobo.pdfIn PDF document text
    • http://saxonrt.hu/img/userfiles/files/jafizakazalokadekerada.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161384ace8bfa8---wusokarebiluvifaximon.pdfIn PDF document text
    • https://mptradingcompany.com/userfiles/file/23224045750.pdfIn PDF document text
    • http://autodilykanka.cz/cmsimple/images/file/64907218265.pdfIn PDF document text
    • https://topupdana.com/contents/files/filelalujagamasufujid.pdfIn PDF document text
    • http://www.gulbaharsigorta.com/contentData/file/27115165095.pdfIn PDF document text
    • http://aromata.ru/upload/files/63109265136.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/cbf6b1a89a9c3060e5dcde91a1f58c56/torazugedijim.pdfIn PDF document text
    • http://wordtmann.beckbauer.eu/ckfinder/userfiles/files/13235637433.pdfIn PDF document text
    • http://rnralpha.cz/res/file/fovepu.pdfIn PDF document text
    • http://www.sas.edu.mn/ckfinder/userfiles/files/legekalujodawexezegajuki.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16142c396e5516---96505624507.pdfIn PDF document text
    • https://kochitaxirental.com/ckfinder/userfiles/files/86137093608.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/52f90610164f43b97cc7d214c2b0519d/47624307749.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143193362a1e---xasogejebimiwezofewav.pdfIn PDF document text
    • https://ruta.hu/ckfinder/userfiles/files/tepanamad.pdfIn 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_off0000b6c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ced8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCED8 10712 bytes
SHA-256: 5b41e929c31d2a2284923d3ddd1bf7b4778a54c3e01c88876c03f1490b7d8d9c
font_02_sfnt_off0000e720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE720 16212 bytes
SHA-256: 7f5f221fb336b6040344e526ba85f35968cb288eae421202cbb903e2c6632b6e