Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c7cb5d527e14b04…

MALICIOUS

PDF

71.3 KB Created: 2021-09-14 02:52:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1fa404de10a71feefed94bb5af5d1428 SHA-1: 7c485be24779f0fc5361b124d71b4f829f1d56ba SHA-256: 8c7cb5d527e14b04ce1b253cf87785c44e2b942747028ecfd998fc47074b1c6a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://noriupapildu.lt/ckfinder/userfiles/files/dasijinegorubule.pdf In PDF document text
    • http://unseretochter.com/images/file/dulelupuxinamufinelofax.pdfIn PDF document text
    • http://ellissi.org/userfiles/files/zemubumatebisugijulabum.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/6167a1afb24bc7d76514dc430406a413/vusogewej.pdfIn PDF document text
    • http://rivucota.com/upload/files/wizab.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16134f7b3cdad5---86415886360.pdfIn PDF document text
    • https://lolakarimova.uz/ckfinder/userfiles/files/17310413893.pdfIn PDF document text
    • http://arucax.am/user_images/file/62762445177.pdfIn PDF document text
    • http://art-lan.ru/uploads/assets/file/45672969316.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/leruvesowaxejedozatesutow.pdfIn PDF document text
    • https://svltv.in/userfiles/files/27171019043.pdfIn PDF document text
    • http://devison-matras.com/upload/file/88526692076.pdfIn PDF document text
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/6600542713.pdfIn PDF document text
    • https://mehfermobilsaglik.com/userfiles/file/63108095189.pdfIn PDF document text
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/puvijemo.pdfIn PDF document text
    • http://barrospizzadb.com/uploads/files/koboxugejasa.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f85f427dad---63588317735.pdfIn PDF document text
    • http://vtaky.sk/media/file/75119543022.pdfIn PDF document text
    • http://barbusci.it/maisUserFile/file/35496571713.pdfIn PDF document text
    • https://cdmsig2.com/ckfinder/userfiles/files/bozewumajevadekez.pdfIn PDF document text
    • http://vectorma.ru/uploads/assets/file/63778194433.pdfIn PDF document text
    • https://samoinstitute.mn/uploads/assets/file/wujonawulatenif.pdfIn PDF document text
    • http://giadinhlaurenso.org/upload/files/guvirijolovape.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=spore+download+apkPDF link annotation
    • 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_off0000b1eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1EB 10280 bytes
SHA-256: ee9586bf6203276a8946e51191b2da145fe3738cd2f1cff2fd0c1d4bfe759a77
font_01_sfnt_off0000c936.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC936 18268 bytes
SHA-256: 4f344065bd8a754146eb11172ff65d72db9ae18e119d28420c85a9ab5ca02026
font_02_sfnt_off0000f79a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF79A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1