Malicious PDF — malware analysis report

Static analysis result for SHA-256 99ffb99c6d25772c…

MALICIOUS

PDF

92.4 KB Created: 2021-09-06 22:59:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8cff5264f6ac4dca358bd2fdd777b453 SHA-1: 8f3e0578df4b6c0150d21febb3bd024cfa8aeb12 SHA-256: 99ffb99c6d25772c2d61ff832f44d025bc7c79785296a71f697901ee27e7e67f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/a3aa55331933f541149069b26fc9f95d/seselanibezatajurupolofe.pdf In PDF document text
    • http://llux.vn/uploads/files/vunewubadogipegiverezisop.pdfIn PDF document text
    • http://chandigarhdatarecovery.com/files/file/68443853291.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/6df7ad714c5ab448139e9a0c1e8cfd0c/95960918483.pdfIn PDF document text
    • http://studiodabo.eu/userfiles/files/87684285017.pdfIn PDF document text
    • http://blesk-stroy.ru/userfiles/files/93095518934.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/45519196846.pdfIn PDF document text
    • http://maxtarget.by/ckfinder/userfiles/files/15839403743.pdfIn PDF document text
    • https://dejavuruse.com/userfiles/file/ronivutenupemonamizov.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608a52313ab0f---34726766763.pdfIn PDF document text
    • http://hardiebase.com/uploads/assets/filefile/ludaxituxamegeniwesiv.pdfIn PDF document text
    • http://www.samlab.com.tr/wp-content/plugins/super-forms/uploads/php/files/mpg1so2mseqi3enrgu459g8n5a/kinuremopumikejowo.pdfIn PDF document text
    • http://www.premiumimport.nl/ckfinder/userfiles/files/49437018589.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad1d56dd413---23485525683.pdfIn PDF document text
    • http://ambulatorioveterinariocamali.com/userfiles/files/24773760007.pdfIn PDF document text
    • http://kayapaliinsaat.net/file/zikodururobidopiri.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089af7b8292b---wemomom.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/91f8c8b57d323f7cbc2c815431fee4ac/19828878190.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/88903266250.pdfIn PDF document text
    • http://businessvaluationapp.com/fck_files/file/wawolewalepafidopuw.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/79c14dd0669fa0a1bb2f77c2d019f7e0/16088806649.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/xevixuzu.pdfIn PDF document text
    • https://datatech-int.com/userfiles/file/sagisaw.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/i7usi8kfguimh21q9i87p276e3/85379682849.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=le+livre+scolaire+3%C3%A8me+fran%C3%A7ais+pdfPDF link annotation
    • 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_off0000fbb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBB6 21000 bytes
SHA-256: 2a20b088961bd5dcd0daeec4e14dca08baba3b1182200ce1f6808bb02d30e623
font_01_sfnt_off00013058.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13058 11232 bytes
SHA-256: 472e0820e470c2185d7bac5ce4464982a61febeaa9050427152acc679d228d4d
font_02_sfnt_off00014a0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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