Malicious PDF — malware analysis report

Static analysis result for SHA-256 750c953b55ffe287…

MALICIOUS

PDF

78.0 KB Created: 2021-09-08 08:23:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 62c8e06d245ac395a1aab4cef8befeb2 SHA-1: 33fa3efd6eb115443d6e7ebc758c50dcf4027536 SHA-256: 750c953b55ffe287332f07dac28fb1b8fc6f7cb83114e97226f9047b32538999
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external URIs and links to compromised WordPress upload directories, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. The document body is unreadable due to encoding, but the heuristic findings are sufficient to determine its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9844

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 https://smidgel.ru/uplcv?utm_term=new+cutting+edge+pre+intermediate+student%27s+book+pdf+download PDF link annotation
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/gqheuedelm49pne7o5cl0m0fv3/wujurew.pdfIn PDF document text
    • http://zonweringbelgie.be/ckfinder/userfiles/files/25468864505.pdfIn PDF document text
    • https://alteanetworks.fr/img/file/23644693670.pdfIn PDF document text
    • https://doanandieuduong295doson.vn/namthuan/images/news/files/74580998729.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/g47lvhrsjob1eq0d5h82ourck7/1788114452.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f612f2575e---32948929821.pdfIn PDF document text
    • http://jerseybankruptcylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dazuboriwe.pdfIn PDF document text
    • http://derkwoo.com/upload/editor/files/68747392591.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/98a8c9cae4207e5d5b89ce089e2639d2/26735024292.pdfIn PDF document text
    • http://hotelpenza58.ru/ckfinder/userfiles/files/63347963753.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160d1ab00aafcb---28951741579.pdfIn PDF document text
    • https://cpsguffanti.com/uploads/file/5286025112.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/160796b701a7a2---torosaxitudenaw.pdfIn PDF document text
    • http://www.proyecpapel.es/ckfinder/userfiles/files/7238526339.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/8due4dtb77c9l8210vrlebm4g7/57438428687.pdfIn PDF document text
    • http://cnex.cc/images/blog//file/78161801944.pdfIn PDF document text
    • http://branonperformance.com/ckfinder/userfiles/files/67514322621.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/kilujadikiteti.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/f5lfj4g20icpo88pra7l8tnjbn/giselurebeleledad.pdfIn PDF document text
    • http://qataminational.com/uploaded_files/userfiles/files/nadokipexezeb.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/7b77792288d89a1511e0b02cd944079b/19469483419.pdfIn PDF document text
    • https://preprodpcb.com/userfiles/files/15675163784.pdfIn PDF document text
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/nawow.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1607eabf0dae44---vobusipizonubedagi.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/kegememubafogakajo.pdfIn PDF document text
    • http://rewitex.pl/userfiles/file/2711549404.pdfIn PDF document text
    • http://connect-senior.ch/uploades/userfiles/file/43369939036.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c5ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5AD 11392 bytes
SHA-256: 2f5a94f2ec896563ff555efc5ebb93c7740086804960dd393b6ea2e40ffcedea
font_01_sfnt_off0000e03a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE03A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f84c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF84C 19204 bytes
SHA-256: 7fb8c76d33667ae5e4dc6294662fe9edf210c392244c3ee663a5eb88333f3f58