Malicious PDF — malware analysis report

Static analysis result for SHA-256 16b6dc37476b0ae2…

MALICIOUS

PDF

93.4 KB Created: 2021-09-18 16:15:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9aae7ea47c024b1b1e69a32fac9a3e97 SHA-1: 73ea36acff4e39aa4f84fc23f222f8cf7ab16172 SHA-256: 16b6dc37476b0ae2d48c3840f62465c046002a9efef4d763fc515c19e9af9827
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. Although no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to lure users to malicious sites, likely as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://tantex.org/tantex/tantexuserfiles/file/17142436516.pdf
    • https://yenhuy.vn/upload/files/64234212370.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140e4b64a01f---govogili.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/c84a09b7d2cd278e7e258c218a4d9f2a/64556477978.pdf
    • http://195exim.com/datas/files/55944008313.pdf
    • https://machnhaduong.com/images/uploads/files/gozigobizojuvukuxinumoz.pdf
    • http://carsonpokebar.com/uploads/files/zuwulenibodotujezolojibe.pdf
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/16141c1dc3dfc8---44358912512.pdf
    • http://meble-tk.pl/userfiles/file/vanafupimajojoxuvofisene.pdf
    • https://chatham-ebenezer.ckdomain.com/uploads/userfiles/files/16937074538.pdf
    • https://kaptenhoki.com/contents/files/51746418401.pdf
    • http://think6.net/ckfinder/userfiles/files/20210908232150.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3bf0197fc---gisukab.pdf
    • https://cfaegaianascente.pt/portal/userfiles/files/tulile.pdf
    • https://bahceneryaman.net/public/content-images/files/konoxoke.pdf
    • http://royalwedding.jp/images/blog/file/dituxebafemuvorozo.pdf
    • http://www.contectrade.hu/fckfiles/file/liwomivilenonanebifewu.pdf
    • http://nerezove-kuchyne.cz/UserFiles/File/gopigivigivug.pdf
    • https://qfuse.it/images/uploaded_files/ckfinder/files/1631131975_a01c603532.pdf
    • http://ristoranteyuri2.com/userfiles/file/vanitonugopu.pdf
    • http://natpuedu.in/userfiles/file/30623376784.pdf
    • http://www.niziointerior.pl/upload/file/rurus.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c209494f4f---42780439906.pdf
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16145767462239---82161866340.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=tempest+by+william+shakespeare+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_off00010884.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10884 16792 bytes
font_01_sfnt_off0001209b.bin
5798c5e6f6343afdd903d4918b3d1bbdc29455da152ede6056f49da51795696a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1209B 10932 bytes
font_02_sfnt_off000139c6.bin
b5ff09ed9288d57deb7a2d9f4115bbed309bb91d6224050ca0a54e3391931707
pdf-font-stream PDF embedded font (sfnt) at offset 0x139C6 17852 bytes