Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c8aaed3b4da98fe…

MALICIOUS

PDF

72.4 KB Created: 2021-09-17 21:24:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c8ae08a84591a7c2fbe952a2ef45e4d8 SHA-1: 0708181ff060d276fd12d4b2690039086a7e1ac3 SHA-256: 8c8aaed3b4da98fe51346273e296f3352d8604c8d8fa667471bcd701c722a927
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://coretry.ru/uplcv?utm_term=six+sigma+green+belt+exam+questions+and+answers+pdf PDF link annotation
    • http://markasib.ru/ckfinder/userfiles/files/pizagaluwazipopuxuvagaf.pdfIn PDF document text
    • http://itineraire-consulting.com/ckfinder/userfiles/files/75774783198.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419c1cd4669---55046381670.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/pezutilaxofenaxewudatif.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210910101121.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613e43b9a1bb0---sujijuzaragi.pdfIn PDF document text
    • https://playworkspartnership.ca/sites/default/files/file/24974372222.pdfIn PDF document text
    • https://shoppingplanet.cityplanet.ro/ckfinder/userfiles/files/pujabobirav.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/rotudofumedobav.pdfIn PDF document text
    • http://tiszaikaland.hu/upload/file/25429369075.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/69753545286.pdfIn PDF document text
    • https://cissud.eu/uploads/ck_editor/files/35566846991.pdfIn PDF document text
    • https://hyundainhapkhau.vn/upload/files/nipatadifebukuku.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/kuliparinopunuwusilabixax.pdfIn PDF document text
    • http://streetnn.ru/data/upload/ck/files/derowo.pdfIn PDF document text
    • http://inwallendorf.de/userfiles/file/koxaxepofi.pdfIn PDF document text
    • http://theleadershipworks.com/PO2/UPFILE/userfiles/files/fumubol.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/2cf88fdeb635a9707a4875458ca9941a/fojuxuvu.pdfIn PDF document text
    • https://www.rosebankprimary.co.za/inc/ckfinder/userfiles/files/luvugajuwobiwabobojuvimi.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/zejokovenekokagesudopo.pdfIn PDF document text
    • https://emons-verlag.com/testarea/cwsCMSlight/media/files/tiwukojudifumasapizelaj.pdfIn PDF document text
    • http://danangsculpture.com/uploads/image/files/paxerekug.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_off0000b1e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1E4 11492 bytes
SHA-256: e905f5b789e376671e4a910f1379384706b1f7801038528accbd3fcf511e1f03
font_01_sfnt_off0000cc5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC5D 18536 bytes
SHA-256: 7a0e27d494c6ac59750258d0e2a0634f92624fa37ed99e6d6882c27675c25059
font_02_sfnt_off0000fbfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1