Malicious PDF — malware analysis report

Static analysis result for SHA-256 866a3728866cd0a4…

MALICIOUS

PDF

78.5 KB Created: 2021-09-26 21:13:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b250e5b9e627a13eb1cbe5cec94ff890 SHA-1: 7fa4181e8013db0f8df1ba94b8431894b3523f7a SHA-256: 866a3728866cd0a468f36317038d7c5c982bd199a53ab1de5791a49358117a23
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for initiating malicious actions within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://smidgel.ru/uplcv?utm_term=live+wallpaper+miui+11
    • http://mmbassisiprovince.in/files/js/ckfinder/userfiles/files/86349925124.pdf
    • http://colorfulmedia.de/fotki/fotki/file/79538465209.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/161396dd36d529---kejisefedufutax.pdf
    • https://aordonez.com/images/contenidos/files/xeragufiwebarafatipo.pdf
    • http://anael.fr/fckeditor/userfiles/file/49765524765.pdf
    • https://jaurrieta.net/USERFILES_JAURRIETA/files/92832065993.pdf
    • http://sfalojistik.com/userfiles/file/zujisiwinukedeb.pdf
    • http://rockefellersgold.hu/editor_up/85288462971.pdf
    • http://business-baltic.com/myfiles/dok/12070484158.pdf
    • http://nissanotogovap.com/uploads/images/files/vagawifexani.pdf
    • http://muabannhagiare.net/images/uploads/files/goxibuxineki.pdf
    • https://insinkerator.us/images/uploaded/file/jabumixumemofirabuvidusi.pdf
    • http://getvisa.ru/images/File/tekot.pdf
    • https://aneri12.eu/res/file/dumisigugorogogobabe.pdf
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbfe91dcfa---xoman.pdf
    • https://brothers-music.com/ckfinder/userfiles/files/90890451416.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/417540fb159ab653678c67d7793e899d/wowapowum.pdf
    • https://redengewinnt.com/userfiles/file/pukirudobod.pdf
    • http://fujiya-la.com/uploads/files/gabiwisamivi.pdf
    • https://academiesutherland.com/userfiles/file/rusuxiwelirosajibonugar.pdf
    • http://ourgans.org/userfiles/files/xowekibo.pdf
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149fc49d9faf---namikobokiga.pdf
    • http://cathyourhair.nl/js/ckfinder/userfiles/files/81228980482.pdf
    • http://xn--hy1bt45apoap01a.net/jangheung/userfiles/file/9237053119.pdf
    • https://travelworld.ro/userfiles/file/29243518798.pdf
    • http://www.cottagegrad.ru/files/file/tijoligudanesup.pdf
    • https://woft-dining.com/webroot/editor-uploads/files/92113978786.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_off0000c8c1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C1 16792 bytes
font_01_sfnt_off0000e0d8.bin
33a0d42bafaa26752fad5a47f9d3fce0ae186da58bd3cd0fb7a9e4426720b3fb
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D8 10184 bytes
font_02_sfnt_off0000f7b0.bin
d8ae35b4002883556e2f3356347e64a680941cb570f9d899fd16456e9e365bd6
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B0 20240 bytes