Malicious PDF — malware analysis report

Static analysis result for SHA-256 151737c3711b278a…

MALICIOUS

PDF

87.5 KB Created: 2021-09-01 23:53:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4dd1e44b2b3cb1f924161f91e0013b77 SHA-1: 3c33825d15bd631a30bd00fcff0014a129a9a2f1 SHA-256: 151737c3711b278ae71284ccf9a5e1454a4defd78570475e81da6c10ed6568c5
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 uploads or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, suggesting an attempt to manipulate search engine results or redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9873

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 http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/88971667817.pdf
    • http://hayatteknoloji.com/webimage/file/74788564769.pdf
    • http://daiichilogistics.com/uploads/news_file/mopotalaxu.pdf
    • https://tsydesign.com/userfiles/jws/files/81224421597.pdf
    • http://caphegiabao.com/upload/fck/file/67585249788.pdf
    • https://nutricount.cz/UserFiles/File/pinomulunevoxum.pdf
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/d9a78b4678153e2b153a21b554bee87f/vosideneti.pdf
    • http://bertrandetgastineaudesigners.fr/userfiles/file/tixekuwodufisiwelidi.pdf
    • http://worldcar.jp/userfiles/files/wopukutuna.pdf
    • https://fiberglasssupplydepot.com/userfiles/file/pevupurage.pdf
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/902cf441c4256b67f64bb7e016e2bd5b/75695408705.pdf
    • http://ttmplus.com/userfiles/files/66042241377.pdf
    • http://jingluo.net/uploadfiles/files/80833834942.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16083870398b43---setubegimev.pdf
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/b39cff76d7e59d5275112eb9a67e9afe/mifusorurobok.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee3265330d---42170328990.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/50ae5bb7f9d9bdc364ce24e77499bd5d/15239875882.pdf
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfcf3869aec---23632861358.pdf
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608f0405f1f15---50626862055.pdf
    • http://szwygs.com/upload/13246227701.pdf
    • http://ctyrkolky-gamax.cz/data/dokumenty/vidadujenin.pdf
    • http://limeitec.com/upfiles/editor/files/34695032909.pdf
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609845e9e74d4---17195398457.pdf
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/2ip6840pipfj4l5go6sfq6hich/93224805020.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4a2eae316---52532026841.pdf
    • http://holmeslawfirm-iowa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mafobolumuxever.pdf
    • http://minipit.com/data/files/93516715929.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=home+remedies+for+sulphur+burps
    • 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_off0000f306.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF306 16792 bytes
font_01_sfnt_off00010b18.bin
9b4fc8e51b87181d0e0ded4344f1b59940e4e0c6aaf916486bbec70fb5c29e70
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B18 17004 bytes
font_02_sfnt_off000136eb.bin
b7201220b9ebffd66e281810cc00f753f1614630a2eb4d051efeb35277d084b3
pdf-font-stream PDF embedded font (sfnt) at offset 0x136EB 10632 bytes