Malicious PDF — malware analysis report

Static analysis result for SHA-256 87d5fb4e773146c9…

MALICIOUS

PDF

73.6 KB Created: 2021-09-08 01:42:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 96029ffa0b30fd64737857cffc48b1ac SHA-1: 748ab4a676c53edd160691c561f85cdb5b44428e SHA-256: 87d5fb4e773146c9aa12c33042b68be76f45c81d002012ad9cb23a66382acd28
156 Risk Score

Malware Insights

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

This PDF was flagged by ML classifiers and ClamAV as malicious, indicating it's likely a phishing or malware distribution lure. The numerous embedded URLs point to compromised websites, suggesting an attempt to redirect users to malicious content. The file's structure and heuristic firings indicate it functions as a link farm on disposable hosting, designed to obscure the ultimate destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 http://ks-puyuma.com/CKEdit/upload/files/jeboluzedugip.pdf
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160db3bdfe345b---gexanodikefoxasikaf.pdf
    • https://baxsporthorses.nl/userfiles/file/63227596945.pdf
    • http://lumieretvie.com/userfiles/file/95770212361.pdf
    • http://botosani.ro/img/uploads/file/lezoxifokesegotafake.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/5bf77cb14b0ceb73602cdeb85b50bd20/98156982948.pdf
    • https://khyatiinfotech.biz/ckfinder/userfiles/files/38102012814.pdf
    • http://www.aportecnica.com/imagenes/editor/file/33106976110.pdf
    • https://kfmaccounting.com/webroot/img/content/files/42701975194.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160875872d24a6---felosofuwe.pdf
    • https://eventpro-kontraktorpameran.com/uploaded/files/63992924170.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098f5cfef022---pasejoruv.pdf
    • http://himalayakebab.irafbrothers.com/shipinc/userfiles/files/rumabuve.pdf
    • http://mondoacquapiscine.com/userfiles/files/badudedepuvoxun.pdf
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/jobolavizowu.pdf
    • http://btfa.tw/upload/files/gokizamonuxapumalimusared.pdf
    • http://csc021.com/userfiles/file/20210704075012_7gzyja.pdf
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/vc3hkfrl3j9g3tjrm70k3cp846/64755662395.pdf
    • http://fujavietnam.com/images/Download/51867132878.pdf
    • https://karapinarinsaat.net/userfiles/upload/file/kikekaz.pdf
    • http://edwardfmcgintypa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/23355444783.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=stanford+clarinet+concerto+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_off0000b9e1.bin
5fd96449105a56ecfb44c01e8b1215c82706d56dc11c8101f9c4718a8585c9a5
pdf-font-stream PDF embedded font (sfnt) at offset 0xB9E1 18220 bytes
font_01_sfnt_off0000e906.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE906 16792 bytes
font_02_sfnt_off0001011d.bin
5d0bf07d71ffe2d00e45c405079a098e1dbf5f69f5383c54de03f2bb1ca4adab
pdf-font-stream PDF embedded font (sfnt) at offset 0x1011D 10520 bytes