Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc440f449dfdc5b5…

MALICIOUS

PDF

90.3 KB Created: 2021-08-08 07:54:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 48389124a4a1aaf2b357c1822adad5be SHA-1: 41c9fd0fae1d0a64ddac32c106c001349ce94f27 SHA-256: dc440f449dfdc5b55a69a430b2cd9eee42057940a22487c9e8aa61a377c5e2ec
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, 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. The presence of these links and the overall structure strongly suggest an attempt to lead users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 https://bbu.vn/Images_upload/files/63076347596.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/16074dc6d46b76---wovejevanowikulibovove.pdf
    • http://merwepizza.com/upload/file/watutenalitomunex.pdf
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070b2e7cd597---buzamoxokoj.pdf
    • http://www.nbc.com.vn/ckfinder/userfiles/files/wigivorupumexaxelifikotit.pdf
    • https://cardion.dk/gfx/fckimages/file/40596170155.pdf
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/las5vf1iutc8hejmir35e44pag/61238184778.pdf
    • https://windsbs.biz/files/file/panudobe.pdf
    • https://tapetcenter.ro/app/webroot/files/userfiles/files/xuxesedoxirasozafaduw.pdf
    • http://salkim.com/userfiles/file/bumit.pdf
    • http://trustarshida.co/cache/fck_files/file/19987249610.pdf
    • https://ecoretras.com/file/1260681995.pdf
    • http://printrun.nl/userfiles/files/78346679417.pdf
    • https://clubesolbra.com/uploads/files/59645075990.pdf
    • https://marbellamohali.com/wp-content/plugins/super-forms/uploads/php/files/06b608f1a8bbc5a475a37f60b1b4d31b/38607098530.pdf
    • http://solyaris.pro/admin/ckfinder/userfiles/files/51403977249.pdf
    • http://www.teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/51283546792.pdf
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ecacba4087d---63141204029.pdf
    • http://ottotech.center/userfiles/file/88175614091.pdf
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608580a5e9c6a---76797161534.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072040105134---teguziduwabutegezevor.pdf
    • http://autavrabek.cz/obrazky/file/27883857136.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=supersu+pro+2.79+apk+free+download
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00010ac4.bin
cfb1bebaa56dbf372651f5796151a567536a9c3f1850ddc22657dc5c11820697
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x10AC4 18704 bytes
font_00_sfnt_off0000db62.bin
07e328707d6aaace45f1a5c3131a54960ffb4c7b8f1ef5b94bb6a3463baa281c
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB62 18120 bytes
font_02_sfnt_off000128f3.bin
2f4d3a1c65f69929a35eafeb638eab3ff01f5b740701d422642c28b446fb8038
pdf-font-stream PDF embedded font (sfnt) at offset 0x128F3 11060 bytes
font_03_sfnt_off00014303.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14303 16792 bytes