Malicious PDF — malware analysis report

Static analysis result for SHA-256 b16dd30608ca4689…

MALICIOUS

PDF

88.3 KB Created: 2021-09-08 20:50:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1abca7ebfb15a70ce5d7d1ec4b9c6d65 SHA-1: c606259b164127608121ed6d253e5d48e16e6819 SHA-256: b16dd30608ca468929f4d8b64266f35f613db3b820a7e6157d0b71568fd1444f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. While no scripts were directly extracted, the PDF structure and its nature as a lure suggest potential for embedded JavaScript or other malicious content to facilitate the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://xmzs.org/userfiles/file/dalavosazusuzo.pdf
    • http://buyyoutubesubscribers.com/ci/userfiles/files/68185586849.pdf
    • http://gdlejia.com/uploadfile/files/20210907_181622.pdf
    • http://kmjmt.com/news/upload/file/210908152008492555g4gnj6.pdf
    • https://okazdedziecko.pl/_files/Media/file/fomagopexajelolodura.pdf
    • http://musicfriend.vn/public/default/ckeditor/files/butojisunibosifaseta.pdf
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133eded8d466---21762332539.pdf
    • http://dianacb.cz/userfiles/file/mizawopore.pdf
    • https://www.hippocratio.gr/ckfinder/userfiles/files/lobimixap.pdf
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/0ead5a0feb0f1ad40149cfd3518f2d25/koduxabiruduvojototexat.pdf
    • http://honderhotel.com/UploadFiles/FCKeditor/20210902215303.pdf
    • https://0900107678.com/upload/file/vejapaxovotibipolofa.pdf
    • https://www.highlandernepal.com/assets/ckfinder/userfiles/files/sepixobawixovobena.pdf
    • http://ipea.kr/userData/board/file/balibuzimolozez.pdf
    • https://mihalex.by/files/files/katidemilinowalepu.pdf
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613141d4eec8a---xemorim.pdf
    • http://robvancampen.nl/userfiles/file/sasipareja.pdf
    • http://travelshops.pl/userfiles/file/26152049835.pdf
    • http://josephfellerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tilomadufirevewa.pdf
    • http://oldadmin.k12cart.com/media/files/jitilerizodojadixi.pdf
    • http://1night2daytour.com/ckupload/files/sozosafurenot.pdf
    • http://starwindows.ie/ckfinder/userfiles/files/pozanepejufirubed.pdf
    • http://p-jtech.com/userData/board/file/jexapaz.pdf
    • https://dobski.pl/userfiles/file/komuwa.pdf
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/e63fc74f7c46cc4b99f34f72e41b85ee/burazidibidegatidezite.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=manual+informatizado+siscoserv+m%C3%B3dulo+aquisi%C3%A7%C3%A3o
    • 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_off0000eadb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEADB 16792 bytes
font_01_sfnt_off000102f2.bin
e5e273317ef933f699d08c830bb5efce999b8b27abfe91d009510bc78c218648
pdf-font-stream PDF embedded font (sfnt) at offset 0x102F2 11604 bytes
font_02_sfnt_off00011d63.bin
02af8a1cb9565fe04b8287cae2b8dc9c3bb71518991b9687fb3e4080ff633f79
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D63 20840 bytes