Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb4c73d3dbcc0765…

MALICIOUS

PDF

92.0 KB Created: 2021-09-05 23:27:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f7658b1404c436cfb32cee1fb03bf382 SHA-1: 30ba03cfa073e8eac000a6cd070bd518c3f01a73 SHA-256: bb4c73d3dbcc076570de322e4ca11df7e3b59071131428f1702df8e56c654a6e
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised websites or disposable hosting, suggesting a phishing or malicious redirection attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.ksmt.edu.np/assets/ckfinder/userfiles/files/21210378545.pdf
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/leropemovaxe.pdf
    • http://homestationrealty.com/userfiles/files/60441405919.pdf
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bf4aba36bb8---15312333651.pdf
    • http://centromp.it/userfiles/files/68673436668.pdf
    • http://edsmithestate.com/clients/8/8f/8fcea3baa00381bb68ca4dcda22eb4c7/File/21390309852.pdf
    • https://nasikampung.info/contents//files/rajagumulonera.pdf
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/hsk8rv6dtoj6unad1cbd5fe4ac/wekefenokezuwemudona.pdf
    • http://jarauwerdaenzn.nl/userfiles/file/57468380127.pdf
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/aed20502a6720922d9d568a7572ff33d/sopon.pdf
    • http://aihyang.com/userfiles/file/93887233742.pdf
    • http://akkoryazilim.com/userfiles/file/lajebisiw.pdf
    • https://subarini.ro/mm/file/sogaxafijipagudovuje.pdf
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b9793f1c878---jitakixoguwapajawelofiba.pdf
    • https://tnmkor.com/FileData/ckfinder/files/20210825_72CDA081D6544419.pdf
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/16d1ea60e264f3b0db559f85c49a5388/37561441671.pdf
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae7f928e845---kanup.pdf
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/62e81bd9bf0d86066b3ac8af67d01da6/48934948493.pdf
    • https://acrgroup.nl/userfiles/file/22311201509.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/n4hr12776qfqkflrfq9ll2tum4/39068894513.pdf
    • http://nenkin-t.com/upload_img/ck/files/pagefexon.pdf
    • http://eia-edu.com/userfiles/file/pewirixunolesor.pdf
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/14bb97abce8796e09b869fdebde47801/fivalulozovazelaparufasu.pdf
    • https://tekartltd.com/upload/files/lefuwotupolerafo.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b2ac8282462---48555989683.pdf
    • https://kogan-photo.ru/wp-content/plugins/super-forms/uploads/php/files/a4c06ddf7262c3ba72c648a14881d84e/8631944541.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=discrete+probability+distribution+word+problems+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fbe2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE2 16792 bytes
font_01_sfnt_off000113f4.bin
02d92f9a6e2292e5af823b2c28f11942f5d318a93b1d2c9827a3a9296f2ca200
pdf-font-stream PDF embedded font (sfnt) at offset 0x113F4 19804 bytes
font_02_sfnt_off000147c0.bin
2754c2f11fb96bc7b3ef0b733f95e4cd9c4a4cb16e476c54b925478a71315c01
pdf-font-stream PDF embedded font (sfnt) at offset 0x147C0 11220 bytes