Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb52a680f4e38aca…

MALICIOUS

PDF

84.0 KB Created: 2021-06-25 22:32:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f28a0064da5161144a8270cb00d9d637 SHA-1: 46cf6608fc7650bf8340b97c7b84a75e9621f625 SHA-256: cb52a680f4e38aca6707fe0499150a10d5374906ebf7ebc069c20886e7ee3520
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple potentially compromised websites hosted on disposable domains. The presence of numerous PDF link farm heuristics and embedded URLs strongly suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/26486b0afb39516b14c0434b9ac1c9a5/40313821539.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/qicu6ghlfqctdf68mka4h06nbs/xufugetavetenuvezowusami.pdf
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a65c4514cca---29924593029.pdf
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160a87dbb9fd34---16178175999.pdf
    • http://elma1.ru/!upload/files/2427307501.pdf
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160945f8423eda---jororotipunizawuluxifimu.pdf
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/e26c79abbae340c96358980bf8ef7651/wevejepoverinodifobi.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/cc219bff76a7bab6e0092bd5036fb320/zarox.pdf
    • http://amazingindiaphotos.com/amazingindiaphotos//upload/fckimage/file/57066956795.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a70c7bc0fd2---begegulut.pdf
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608116b6e9057---87894000976.pdf
    • https://phuketwebstudio.com/ckfinder/userfiles/files/11254457374.pdf
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b648ae8c0f3---82655686491.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adf41ee80ef---laletoji.pdf
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160bb3a4c1876a---wujibaju.pdf
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/p77kn816dumkk79t7lp21c3guo/boxowi.pdf
    • http://kangs78.com/clients/66216/File/36432255599.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=best+mac+snipping+tool
    • 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_off0000e642.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE642 16792 bytes
font_01_sfnt_off0000fe59.bin
62114375aa713fb0799558cbe27459c22fe9b6def88aba7f79611edf43994da8
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE59 10668 bytes
font_02_sfnt_off000116d1.bin
f6b4e375520a30bd1d1bf5a63b41ac8c64130145d3330bfe87e107fef37963d2
pdf-font-stream PDF embedded font (sfnt) at offset 0x116D1 17044 bytes