Malicious PDF — malware analysis report

Static analysis result for SHA-256 b73d202e5c7150ba…

MALICIOUS

PDF

85.9 KB Created: 2021-09-01 23:53:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: df1e14a640b84bdafd129b3b3b14835a SHA-1: ff4beacf0722f567de205fbe121b8447603e79c8 SHA-256: b73d202e5c7150baf009d0c6a6934d260c569d8740b4ddd214cd7aa08f3a05d0
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document that contains a large number of links to external resources, many of which are hosted on compromised WordPress sites or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The primary attack pattern involves a link farm designed to trick users into downloading a malicious PDF, potentially disguised as a legitimate file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 http://ambulatorioveterinariocigliano.com/userfiles/files/wamopojefuwolabu.pdf
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/2b18d403cbcc0e200527d42346d381b0/ruxawurupusum.pdf
    • http://tatnhapkhau.com/ckfinder/userfiles/files/gatizexomatifaduvudak.pdf
    • http://suachuaspa.com/upload/images-content/files/mekuxabejewexupedonone.pdf
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/7f56ba88a46b94b0cbc2fe6287cb489f/tavakowajinekonudo.pdf
    • http://gamjagolla.com/uploads/files/rejusezobegigikemepudiluj.pdf
    • https://fo-prefectures.com/pages/files/35869534192.pdf
    • https://www.helmmsp.ca/wp-content/plugins/super-forms/uploads/php/files/b337e1cd4ae42000f150879a8f0f2bc0/naxerivuvidosirifaxu.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16126227d0448f---nugevexazawozaban.pdf
    • http://kurdumovldpr.ru/uploads/files/95690257408.pdf
    • http://aj-freight.com/ckfinder/userfiles/files/92569326472.pdf
    • http://brookhavenclassof1967.com/clients/0/0c/0ca802fc87877f8c548ddf85495caeb2/File/mimifoto.pdf
    • http://vestmorecapital.com/images/epost/xadovutiligog.pdf
    • http://mirutte.com/newsfiles/files/lixeregama.pdf
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1610bd58acface---kigikafuretevifuguxaninu.pdf
    • https://aartipalette.com/userfiles/file/20509747306.pdf
    • https://hchoanglong.vn/userfiles/file/1686964261.pdf
    • http://vistobrasil.net/uploads/file/fofezu.pdf
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/jnllenoge8m59gpm2537b9tgq6/37582678469.pdf
    • https://bouveau-consulting.com/userfiles/file/tufamalukojulozasutija.pdf
    • http://unityproductions.com/upload/files/69649735209.pdf
    • https://botroul.be/uploads/11870754737.pdf
    • http://dptour.net/bot/ckfinder/uf/files/50249242966.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=free+download+ms+word+to+pdf+converter+software
    • 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_off0000e901.bin
27985e40ae3f90bda2f8d714b684e453547a6612ab8e15b9e5177215156b9ada
pdf-font-stream PDF embedded font (sfnt) at offset 0xE901 10820 bytes
font_01_sfnt_off0001020d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1020D 16792 bytes
font_02_sfnt_off00011a1f.bin
52f68d9392e6ba8cf798a1c626fdf1e928b27150da9db6f4f366895f03a442a9
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A1F 17220 bytes