Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb4be91eecbce405…

MALICIOUS

PDF

97.0 KB Created: 2021-09-22 11:15:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6577c67be6bdfa8c2aa73e3625c29ba6 SHA-1: 4b637178998b67e8a58a0c72558509a711b18b34 SHA-256: bb4be91eecbce40513fe08ddf5f784b7b67ecb6e53dbbd35276c47f8a5977f95
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of external URI heuristics and link farm indicators reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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://cructi.ru/uplcv?utm_term=brian+tracy+eat+that+frog+summary PDF link annotation
    • https://semangkamerah.com/contents/files/zuboxoro.pdfIn PDF document text
    • http://aviteksural.ru/admin/ckfinder/userfiles/files/pujematulomunarikimarezo.pdfIn PDF document text
    • https://sudahhabis.com/contents/files/zidujurerufupimozojoge.pdfIn PDF document text
    • https://tierlistei.ch/downloads/66499254688.pdfIn PDF document text
    • http://oryginalnedekoracje.pl/userfiles/file/80987432912.pdfIn PDF document text
    • http://czerwoneiczarne.pl/files/file/39513025265.pdfIn PDF document text
    • https://konyaalotaksi.com/userfiles/file/75578744295.pdfIn PDF document text
    • https://redac.ch/upload/vakep.pdfIn PDF document text
    • http://cybernet.asia/UserFiles/File/rutotos.pdfIn PDF document text
    • http://studiorumeo.it/userfiles/files/sibevenisofevirijojino.pdfIn PDF document text
    • https://wineuniverse.us/userfiles/file/lugekiwulifav.pdfIn PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/davidi.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ad6f395c02---bokurekum.pdfIn PDF document text
    • https://cfaegaianascente.pt/portal/userfiles/files/dulubofigaxoguxaziwus.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/654646af0d291bb92b7a6e723af5bca8/27834062879.pdfIn PDF document text
    • https://ruiguoex.com/upfile/files/2021/09/09/40278920649.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/7nnm6fmcmm23qn9tcahj9t57oh/49326518689.pdfIn PDF document text
    • https://ruh-center.ru/userfiles/file/34690316680.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/jiduzikimoluruwidunajoz.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613440cea7fd6---88850836085.pdfIn PDF document text
    • http://geasit.it/userfiles/files/7841894652.pdfIn PDF document text
    • http://thamcohoaian.com/webroot/img/files/sukuxogulixu.pdfIn PDF document text
    • http://mijinmotor.com/fckeditor/userfiles/file/venarudawenubaro.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_off00011141.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11141 11004 bytes
SHA-256: 7dff019628e0f7001b1a28a886a543d2dcac524c2009a53dd6483c2afa7372f7
font_01_sfnt_off00012aba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ABA 19804 bytes
SHA-256: 3dc64a1de29139ca28838ec5a6968791c743cfce125e3103417b7cc18fbe7c5c
font_02_sfnt_off00015e2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E2F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1