Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b774f7815353711…

MALICIOUS

PDF

80.0 KB Created: 2021-09-19 23:43:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b509d9d0393aa2f94b7cd823ba862415 SHA-1: 1a0c537e59be14fe1f819e44d12788661e6d45bd SHA-256: 1b774f7815353711034f183e99aa52cbb9acf709a0a1e78535455f01e67e750d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple potentially compromised websites, including one hosted on a compromised CMS upload storage. The presence of numerous unknown URLs suggests an attempt to distribute phishing content or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://hospvetcentral.pt/site/upload/file/74729600293.pdf In PDF document text
    • http://sns-russia.ru/userfiles/file/mikugutipojolanidovax.pdfIn PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/vakenurewoxoxuriluvinawu.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-9-18/20210918035735673353.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/2uuaqii22fkc8vhgvi78c310mg/zabusiga.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/fiseminumumitewawite.pdfIn PDF document text
    • http://bacvietexpress.com/upload/userfiles/files/xetovefogawejaxalopot.pdfIn PDF document text
    • http://ageddfjtjgrade.pretty-match.com/upload/files/32877752298.pdfIn PDF document text
    • http://jan-fotografie.nl/upload/files/ledizinumatoraveni.pdfIn PDF document text
    • http://www.de.ruben.pl/ckfinder/userfiles/files/nubebipomame.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d39799a23---vowadop.pdfIn PDF document text
    • https://worldcastlive.com/userfiles/file/55038196680.pdfIn PDF document text
    • https://yauspeshen.com/ckfinder/userfiles/files/tobiw.pdfIn PDF document text
    • https://polenhosting.com/calisma2/files/uploads/20901737555.pdfIn PDF document text
    • http://safetruck.gr/images/file/52529391766.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/goxasirerojivo.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/7035266856.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/jh2inmf2eioo354ft4tiot36p3/99890195359.pdfIn PDF document text
    • https://estatecambodia.com/htdocs/cljr/data/files/xofikewowofo.pdfIn PDF document text
    • http://agisma.ru/files/pages/files/53813575998.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16135f7d11dc26---nemosababanonigudifurilo.pdfIn PDF document text
    • http://interwork.sk/userfiles/file/metimug.pdfIn PDF document text
    • https://techinnsrl.com/writable/public/userfiles/file/40158005188.pdfIn PDF document text
    • http://nebovsem.ru/app/webroot/files/files/gekoxu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=cooking+mama+apkPDF link annotation
    • 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_off0000d53e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD53E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED50 18000 bytes
SHA-256: 0ebb1fd277b38fcf10e7a4c89d01ba65ec51be04afe5f05f0832d55925ca5352
font_02_sfnt_off00011c0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C0B 10172 bytes
SHA-256: 93ca1678efb96f3ae28991a872f15fa0609b75d726bb7641b7929e7c1e9e7ec3