Malicious PDF — malware analysis report

Static analysis result for SHA-256 53417a51785cc69a…

MALICIOUS

PDF

85.1 KB Created: 2021-09-14 07:38:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1504fc7e684023436d14c5f288bad62b SHA-1: a28687f2903a9d1dc9579071a8e116beaf660248 SHA-256: 53417a51785cc69ac39ec2c481c19f1e9a8c21a465391f1c6fcf0edd713b3e93
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The presence of numerous URLs, including those with UTM parameters, suggests an attempt to lure users to potentially malicious sites for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://synerhu.ru/uplcv?utm_term=write+a+quadratic+function+in+vertex+form
    • http://pokewaveanaheim.com/uploads/files/baserokorenet.pdf
    • https://dortmundpools.com/contents/files/wuwemorekexi.pdf
    • http://kozelskadm.ru/files/uploads/files/wulevefigomumotafulikizu.pdf
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161401f799737b---fufirilulezujapo.pdf
    • https://sardavetri.it/userfiles/file/21134321373.pdf
    • https://www.gurkhasfinance.com.np/ckfinder/userfiles/files/dimidosesi.pdf
    • https://gppacdatabase.net/userfiles/file/xudozovebalixijedina.pdf
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/nuxameluri.pdf
    • http://abwessex.com/uploads/files/65932635022.pdf
    • http://elementsgogreen.com/userfiles/file/39097923279.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136be7b8be88---movejuxav.pdf
    • https://gobelsprofil.com/upload/files/29624176135.pdf
    • https://vieclamday.com/userfiles/file/31274774910.pdf
    • https://atlanticcompact.org/userfiles/files/65078927121.pdf
    • http://www.americaninvest.net/upls/files/viburokijozubil.pdf
    • http://okvin.org/userfiles/file/vamanixofef.pdf
    • https://perfecthospital.org/ckfinder/userfiles/files/zuwupifatefegasokewe.pdf
    • https://jordan.si/dokumenti/file/27025532605.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614016b675a0a---vufanitosugakobem.pdf
    • http://galantemontagnana.it/ckfinder/userfiles/files/kakesirinonemakudakep.pdf
    • https://officialbacknumber.org/editor_up/87081864989.pdf
    • https://morganmethod.tuesdaytrader.com/ci/userfiles/files/kuvazovowo.pdf
    • http://muzeumostrowiec.pl/obrazy/file/losuvodopolunazozadebubi.pdf
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db530a8187---jopotuxaperilumuxin.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_off0000e2f6.bin
c2503faf0b858a7fb55bd2b919b913a24b27d85f7fe5347d6cfeeb079a6009f7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F6 10832 bytes
font_01_sfnt_off0000fbc0.bin
72ba63e9f919b55a8d1fb7181c4dddb955326473d1a54452121924d13f86d3d8
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBC0 19416 bytes
font_02_sfnt_off00012e30.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E30 16792 bytes