Malicious PDF — malware analysis report

Static analysis result for SHA-256 9306d6e7f76c0397…

MALICIOUS

PDF

86.5 KB Created: 2021-09-18 09:31:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4239fb55834694baa494bfd528e8f764 SHA-1: a88ef01c8f02e43f8cc2af145b88a7e19cdeb8ca SHA-256: 9306d6e7f76c0397dc85a6a3816bbbd709bea12259f0435a433636207d1a7936
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The embedded URLs and the nature of the heuristics suggest an attempt to trick users into visiting malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=android+blue+screen
    • http://orthodoxvaidikasanghom.org/userfiles/file/fejafe.pdf
    • http://mdfgiare.com/upload/files/letama.pdf
    • https://dukeofmarshall.com/ckfinder/userfiles/files/82625852055.pdf
    • http://wskinbody.com/data/boardData/files/gajubegerikaxuzu.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/5dsaom4317dab995lh98q85ato/dodupusopadivokod.pdf
    • http://fc-junajted.com/upload/datoteke/sexorowilesegokidiv.pdf
    • http://technimexvn.com/images/ckeditor/files/72821181784.pdf
    • https://fiscalonline.ro/app/webroot/files/userfiles/files/80884469730.pdf
    • http://www.prodomasa.com/ckfinder/userfiles/files/jikabepabu.pdf
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144c289244fb---80638437520.pdf
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/d93b7f5ffcf341fc516d62aaeeba4f54/26487814967.pdf
    • http://engineersclasses4competition.com/files/others/sipirugoporaw.pdf
    • https://mastirz.com/userfiles/files/86852527992.pdf
    • http://oryginalnedekoracje.pl/userfiles/file/7430852197.pdf
    • http://ksnjl.com/userfiles/files/85203906322.pdf
    • http://moonlightmontessori.com/upload/files/73268908040.pdf
    • http://hoteldanang.com/uploads/images/files/22259472388.pdf
    • https://roarmysecurity.ro/mm/file/51095491364.pdf
    • https://wildarium.com/ckfinder/userfiles/files/84935710465.pdf
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/161392ce69e55e---biwejow.pdf
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/16141f0ae6b48c---sonaxefujobiletukuvufo.pdf
    • https://v-rshine.com/upload/images/files/69594714197.pdf
    • http://ngocphuocjsc.com/public/default/ckeditor/files/laxuminonamugiviluxokipi.pdf
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/161353e9b4c25b---43094906820.pdf
    • https://tomorrowhubs.com/upload/users/files/zexinaviwexogiposowuku.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_off0000ed93.bin
01343e71dbcc7b0e7206e017d84117cffbd39a2fa3c2866b855f5e5eccae7e2e
pdf-font-stream PDF embedded font (sfnt) at offset 0xED93 18332 bytes
font_01_sfnt_off00011cde.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CDE 16792 bytes
font_02_sfnt_off000134f5.bin
a95d04cf9744cfec152c0a4b860cdf65d2e9d04013aae92543f5213a8720b1c5
pdf-font-stream PDF embedded font (sfnt) at offset 0x134F5 10324 bytes