Malicious PDF — malware analysis report

Static analysis result for SHA-256 71da2f94c08c2723…

MALICIOUS

PDF

84.6 KB Created: 2021-09-17 11:01:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2ca5d50794f4e9c074b30c477a43897f SHA-1: 48e55ee3b2dc720eb9f43374ca9d6b530cd2ea43 SHA-256: 71da2f94c08c27234b2ee98859f29350d9d683ff3401f55ab54f320b8887c7eb
196 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, exhibiting characteristics of a phishing or trojan delivery mechanism. The heuristic 'SE_FAKE_CAPTCHA' indicates the document presents a fake verification prompt to deceive the user. Numerous external URLs were found, many hosted on compromised websites or disposable domains, suggesting a link farm designed to redirect users to malicious content or download further stages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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://infrive.ru/uplcv?utm_term=fake+card+numbers+with+money+on+them
    • https://valerart.com/ckfinder/userfiles/files/xujamepe.pdf
    • https://energiadirect.pl/application/resources/ckfinder/userfiles/files/fiwalumoloxubeliv.pdf
    • https://xn--80apefbdm9ah5g.xn--p1ai/userfiles/wisebinetavawo.pdf
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/gqfacdsicatqpjciq796t7ejfn/mezepinuzep.pdf
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/f92bca400bbdc7460c416343dec13dc8/jikuporolomavalugevuw.pdf
    • http://dralituncer.net/userfiles/file/xugonunewizuwigomusomawex.pdf
    • http://elektro-galerie-hamburg.de/userfiles/file/49554940720.pdf
    • http://steinemann-ag.ru/nimatiwasisoko.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614224db91758---lepagusuvinimebudeb.pdf
    • http://vallovin.it/userfiles/files/nubidoter.pdf
    • http://parvazyab.net/basefile/api203/files/28060695859.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/c30u5lfhappfpvjb887cc85092/6506752527.pdf
    • http://jewelry-shopping-city.com/uploads/files/202109040718239367.pdf
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb592316c6---rafobipezidurani.pdf
    • http://bakersfield.thepokeluau.com/uploads/files/91045884794.pdf
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613f2cb4f05e4---97497086589.pdf
    • http://pawsandtiaras.com/ckfinder/userfiles/files/mixidodune.pdf
    • http://codemessaging.net/ckfinder/userfiles/files/varufomabi.pdf
    • http://agataklimowska.pl/userfiles/file/25547036342.pdf
    • http://mtegl.wsystem.sk/userfiles/files/mokowesuwadukug.pdf
    • http://majortaylorride.info/images/uploaded/file/83430376551.pdf
    • https://serihosting.com/calisma2/files/uploads/lofinonudewaki.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_off0000e3f4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F4 16792 bytes
font_01_sfnt_off0000fc0b.bin
c480f5d3c7c67c86472112ad36591b3a1f5c6659e3d593f280c4c00b9bbd2079
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0B 11100 bytes
font_02_sfnt_off000115d0.bin
bb89539db5ef0d348babdb21af7e2edac242e43b5b6d8498683bd71e34bc3975
pdf-font-stream PDF embedded font (sfnt) at offset 0x115D0 18388 bytes