Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9aa8ce0344b2de2…

MALICIOUS

PDF

100.1 KB Created: 2021-07-23 13:46:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 376d07e5a8c788461a50681be351c7e8 SHA-1: df43498ac50986a31c8c643e73e16fede58b1aae SHA-256: a9aa8ce0344b2de2d9feb6407310533447864a12d956bf1287632f9291d9775b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links. The use of wkhtmltopdf suggests it may be a generated document for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://bioterapiazabiegi.pl/obrazy/file/38641378669.pdf
    • http://biirbeh.mn/images/content/file/fovodakulupuzojubutipijo.pdf
    • http://udmvdpo.ru/images/files/xokijake.pdf
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/5a777ad0c6627047e9ded6f68de9734f/37638237487.pdf
    • http://goldenpeak.it/userfiles/files/45782705162.pdf
    • https://appchecar.com/ckfinder/userfiles/files/16925711450.pdf
    • http://sbhs1967.com/clients/8/89/8985ce50e7417da620f75e2af787291b/File/62851413763.pdf
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a1afe982fb2---55682422704.pdf
    • http://alliusie.com/userfiles/file/91008157073.pdf
    • https://teenvolunteerhouston.com/wp-content/plugins/super-forms/uploads/php/files/2fc926974994d7f512d736e26c237457/pisilinukali.pdf
    • https://hogies.com/includes/template/uploads/file/fususemujeluvelikefifa.pdf
    • http://clubcrudupsonoma.com/clients/1/14/14cf715f5cd05ddba197ceaa5938d7d5/File/wogoxiwapigodetirupujin.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c10c575b48a---95042662765.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfeafc5c1a1---12508811807.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/lgp48g7gmkie67v6f76fral8ja/3755680785.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/abe5ee40f9a6e7672f7141616d4de57e/28337326735.pdf
    • http://ambulatorioveterinariomariani.it/userfiles/files/nufasul.pdf
    • http://calebdobe.com/clients/875189/File/47530655093.pdf
    • https://blsautomation.com/ckfinder/userfiles/files/23071815012.pdf
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1608e386ae1395---wanilaja.pdf
    • http://worldcar.jp/userfiles/files/vulemisegurusumu.pdf
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a0e90a4d2e1---topibuserefifiketejar.pdf
    • https://0900107678.com/upload/file/kejaz.pdf
    • https://eseninternational.com/uploads/files/sufotarepapexisir.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=fraction+pictionary+cards+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_off0001202e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1202E 16792 bytes
font_01_sfnt_off00013840.bin
a428c87d86f5584ee75aebf6337eb3af4e22d7daf4240c0d34c5f6252f2121c5
pdf-font-stream PDF embedded font (sfnt) at offset 0x13840 18472 bytes
font_02_sfnt_off00016900.bin
28a8e1cd9c18417633cd6c29056789786f6a9141321bd037e2c2463305230c9c
pdf-font-stream PDF embedded font (sfnt) at offset 0x16900 10524 bytes