Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b427b97764e6127…

MALICIOUS

PDF

84.4 KB Created: 2021-09-11 08:22:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4e93c4e444d5a8ad4a94c03938446b29 SHA-1: bb39d52512287ab734b0ca18092eefd6d30d57ec SHA-256: 5b427b97764e61271bada5eb3ccb39d9136b4b6b5d066c056d7a44671eb26e84
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The file is a PDF that contains numerous links to other PDFs hosted on compromised websites, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The document body is unreadable, but the heuristics point to a lure mechanism, potentially involving QR codes, to trick users into accessing these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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 http://nanoservice.cz/upload/file/50975169091.pdf
    • http://autolubitel-irk.ru/userfiles/file/36035204900.pdf
    • https://sedefartphotography.com/resimler/files/705273341.pdf
    • http://runnersavezzano.it/public/userfiles/file/zosoxemobifasudu.pdf
    • http://okeefesreef.com/ckfinder/userfiles/files/30260042656.pdf
    • https://lixtech.com.tw/ckfinder/ckfiles/files/digewu.pdf
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/279404b210f5a2852b978b1834aa2076/46973685589.pdf
    • https://kidneystonetreatment.in/userfiles/files/sogel.pdf
    • http://lateonsettay-sachs.org/userfiles/file/liwesevafadofabepilaz.pdf
    • https://guruvinodji.com/Userfiles/file/40644859209.pdf
    • http://tomdythai.com/userfiles/files/povozirokuxokaka.pdf
    • http://benthanhsgfarm.net/images/uploads/files/96899180975.pdf
    • http://rockbond-aac.com/id-admin/fckImages/file/zorapuxedepu.pdf
    • http://kgmda.com/upload/files/pabagoliwenuf.pdf
    • https://cantarefides.ro/admin/userfiles/file/4616985835.pdf
    • http://topstec.com/d/files/lelugixagamujedisajoma.pdf
    • http://globalbizkorea.com/userData/board/file/zufepopidafofoso.pdf
    • http://vikingpaint.com/user_file/file/xepinipi.pdf
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130aef40d97e---pegufefotagilobubalojuxo.pdf
    • http://nickelsgrafikdesign.de/ckfinder/userfiles/files/57985070154.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/reur18sct17041cph12jko0te4/masorobaxasu.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612efd9aed1b7---mavodadodukika.pdf
    • https://benmoonpharma.com/userfiles/file/29763658965.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=android+1+fts+15
    • 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_off0000e7fb.bin
b430f30308ac9be4d4366013a1b57edf8c93c70b554c21d38dd0ec0e8e9198e2
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7FB 17776 bytes
font_01_sfnt_off000115ad.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x115AD 16792 bytes
font_02_sfnt_off00012dc4.bin
b2933d6c4b9477ea2ba2a1b44cab5226cf9926b2b6082e0cb18eee56e7cae007
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DC4 10172 bytes