Malicious PDF — malware analysis report

Static analysis result for SHA-256 903cde1df7c76a69…

MALICIOUS

PDF

88.0 KB Created: 2021-09-19 11:04:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8d630e14f52b1c753d00ee300043e901 SHA-1: dd724fe0a31d6611888e1ff3602a26718052687c SHA-256: 903cde1df7c76a69036109ea4449dc542633f697c56bbdc81179b6965fe91c21
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly indicate a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://allytemp.ru/uplcv?utm_term=xperia+10+ii+comparison PDF link annotation
    • http://jinruily.com/UploadFile/file/20210902044701096.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d27b8c732d---rudakolemowi.pdfIn PDF document text
    • http://asia-test.informacittadino.net/media/files/vufijulikakag.pdfIn PDF document text
    • http://twtipa.com/upfile/files/2021/09/16/179198207.pdfIn PDF document text
    • http://rotang.net/userfiles/file/dijisexegagigisi.pdfIn PDF document text
    • http://angelascanu.it/uploads/file/lipedemenudofi.pdfIn PDF document text
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/simivadimibijobujejiva.pdfIn PDF document text
    • http://myrbacken.se/login/ckfinder/userfiles/files/jifovulagaron.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/rigopugakijar.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/dezodibi.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/964c6caea47f50fa3ed995217d461a0d/misonuxofujidobekoru.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/68292abf565d1d96df918b487fcabc66/dofavazukefazegumitu.pdfIn PDF document text
    • http://thementalhealthadvocates.org/files/userfiles/file/30148797195.pdfIn PDF document text
    • http://www.web-globus.de/ckfinder/userfiles/files/nikemudojudugamalubevifed.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fed0a73820---velukuvusoz.pdfIn PDF document text
    • http://pbhdom.eu/userfiles/file/galibibunal.pdfIn PDF document text
    • http://angelescare.com/userfiles/file/xelegisit.pdfIn PDF document text
    • https://brianhigbielaw.com/UserFiles/file/xunonenepud.pdfIn PDF document text
    • https://24emk.ru/ckfinder/userfiles/files/sudasazukeponedu.pdfIn PDF document text
    • http://brlairport.com/images/file/winenujulenaba.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/t61p2e33vpl8nkkl002qb6gbq2/75134186170.pdfIn PDF document text
    • 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_off0000eeb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000106ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106CE 10572 bytes
SHA-256: d23b6675d48cbccf89ecd72210cb0d3006f0d954678ef81354ed5ade094b6354
font_02_sfnt_off00011eea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EEA 19404 bytes
SHA-256: abf6f5f7cf3547d9698ef491d4794a4339f81f4ea932e235a0511671c10bfe0d