Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8517b69804c7df5…

MALICIOUS

PDF

87.0 KB Created: 2021-07-30 05:35:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 857d5786a61156683d8f2324985bff68 SHA-1: 21eba0bfa5df8cca70df4121aa45b2c94d3866cc SHA-256: a8517b69804c7df5b5de42df3d386d0402f6937e0303b72bf5c0715c7ec87ad2
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised CMS uploads and disposable hosting, suggesting it's part of a link farm designed to redirect users to malicious content. The presence of embedded URLs and the overall structure point towards a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b64dbd5bc47---31840022360.pdf
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/42110341875.pdf
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607e6748d1750---79812097021.pdf
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082c76bc980b---suvawodusalu.pdf
    • http://ideviceplus.nl/app/webroot/files/userfiles/files/bagidekotarawefupi.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/59661637072.pdf
    • https://calmoinc.com/upload/editor/file/44110401719.pdf
    • http://fotografiafrancescosomma.com/userfiles/files/tokarokokuturowusofid.pdf
    • http://tomlitkom.ru/ckfinder/userfiles/files/22520330447.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160830c47a25c8---63334887235.pdf
    • http://ibookingkr.com/FileData/ckfinder/files/20210720_C87BFB42A5081F1E.pdf
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/ef89ea7be4e062e23e7570e9965393c5/ferutosewuvifowomerul.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/50c26bc92ca8f5278960c8467fb72233/bulusumasamidivime.pdf
    • http://ongxoanhdpe.vn/upload/files/93603116359.pdf
    • http://riverbendhay.com/clients/4/4e/4e1cbd84181290ddb66fb035c9950ff6/File/mowejame.pdf
    • http://folientastaturen.pl/_data/file/38871183936.pdf
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/30a9856a0949ec4740ce8e3a732e0004/rutopidasuzojokimapu.pdf
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/97fce59a574ed69658494c3dc2349ed6/49177051958.pdf
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a09e6dc274c---kapax.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160babffa263bf---wuxomoxu.pdf
    • http://wohntraumgmbh.at/wililofefuxo.pdf
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/ea07bddd1082cdf6af1d8e46576982d5/xexuwepojuz.pdf
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/vujubuguvipabadewob.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=ejercicios+de+comprension+lectora+para+sexto+basico
    • 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_off0000ec48.bin
4c5b28f739a1732210b3592b6310d2cc49a34bc02ef4065dbd495bee93656c67
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC48 18128 bytes
font_01_sfnt_off000119e8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x119E8 16792 bytes
font_02_sfnt_off000131ff.bin
1f62be5831f7fe704de98a481b6e03fdfb50a62d6b9b75804f270a0bed97d9c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x131FF 11028 bytes