Malicious PDF — malware analysis report

Static analysis result for SHA-256 83d872d31b87eee8…

MALICIOUS

PDF

82.5 KB Created: 2021-09-19 22:19:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 24763b5353f191a00e55326ce0670d9c SHA-1: b73a30625d90f001ba53510fc1ae32f0282a8973 SHA-256: 83d872d31b87eee83a8b7c2220672c36b7de74d014f6a5c02e06b0941180f836
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised CMS upload storage or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chcial.ru/uplcv?utm_term=scary+games+for+phone
    • http://saigonford3s.com/uploads/2021-09-14/images/files/siboxa.pdf
    • https://gkatsov.com/userfiles/file/dedufirinatape.pdf
    • http://saraswatishikshamandir.com/singhania/downloads/file/tupuxewavitidududifu.pdf
    • http://premo.at/userfiles/file/54188272138.pdf
    • https://goodmix-psc.com/userfiles/files/riwapekagulifeton.pdf
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/7c085610228bc53b514c44a248717a0b/48146409878.pdf
    • https://atpl.aero/ckfinder/userfiles/files/40939166724.pdf
    • http://tauben-buchmeier.de/kleinberliner-schuetzen/userfiles/files/42615112297.pdf
    • http://studio5r.com/userfiles/files/nosugunuxam.pdf
    • https://booknowrentalimo.ch/userfiles/files/65891722607.pdf
    • http://sunwisechem.com/Uploadfiles/files/61537647367.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/g1t6ekta0cpo053rh4j90ivpb5/45732432987.pdf
    • https://inprovitecuador.com/ckfinder/userfiles/files/xukadudokasakekara.pdf
    • https://adsbudget.net/userfiles/file/pofarufirafilanufixuvot.pdf
    • http://cosmosimpex.com/app/webroot/ckfinder/userfiles/files/zemunowefudizuruwopub.pdf
    • http://tantusmarina.com/UserFiles/file/81038110016.pdf
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/f818qutgt61rubabu7ltd66gl8/mesozitenafufusijobadixe.pdf
    • https://www.disbel.es/ckfinder/userfiles/files/xutowekuziraxekuzo.pdf
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/16140dac60fd7b---19983003446.pdf
    • http://epoch-making.jp/js/upload/files/garenarikexusanarakofun.pdf
    • https://pasationtravellers.com/root/FCKeditor/file/dunamagoforinod.pdf
    • https://laatjehuisweerstralen.nl/upload/file/26171417087.pdf
    • http://helderlive.nl/ckfinder/userfiles/files/69477156996.pdf
    • http://tt-ural.su/admin/ckfinder/userfiles/files/wazorub.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_off0000dac1.bin
f12fde4df5814d3b508902eb122eb45f506a8b63cc3ce196e6f8a0800490cbcb
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAC1 10880 bytes
font_01_sfnt_off0000f3c0.bin
8683c5b5acefb93e76a3e1142677fa4629783bde4e53d6ac6bbcd7f356f9eb02
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C0 18980 bytes
font_02_sfnt_off000124b5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x124B5 16792 bytes