Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f57a665e28de95d…

MALICIOUS

PDF

81.0 KB Created: 2021-09-18 22:44:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 323579c6df10965fc999473472bc8931 SHA-1: 1f312416e550c6102eb7cf9d86f3448795a0c8ef SHA-256: 8f57a665e28de95dbfc851f9fd7fcd66ce690c4d634f1074cf9603f49aebc325
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicating a link farm designed to lead users to malicious content or phishing sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://chcial.ru/uplcv?utm_term=major+scale+hand+signs PDF link annotation
    • http://energo-market.ru/sadm_files/jirofanofobijebuzal.pdfIn PDF document text
    • http://architettoletiziamasciotta.eu/userfiles/files/16936251085.pdfIn PDF document text
    • http://houselandia.ru/files/56360607682.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145eb723bc8e---75808698423.pdfIn PDF document text
    • https://censcakmu.org/board/file/files/lajusefa.pdfIn PDF document text
    • http://kindergartenhelden.at/upload/file/30232786667.pdfIn PDF document text
    • http://tnetimes.kr/upload/file///paziwawamogip.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/eqnbpsqq5mrr9v34pg4nju3e9u/60929105317.pdfIn PDF document text
    • http://mamolenasnc.it/userfiles/files/wosep.pdfIn PDF document text
    • https://kanat.com/upload/ckfinder/files/sevanumojijukisidikimi.pdfIn PDF document text
    • http://dalieuht.com/app/webroot/uploads/files/wigirazalesugeda.pdfIn PDF document text
    • http://patrick-vallot.com/upload/files/79295395558.pdfIn PDF document text
    • https://diphong.com/uploads/vegalisewunonujebapamaz.pdfIn PDF document text
    • https://fsbulletsandbrass.com/userfiles/files/77256097911.pdfIn PDF document text
    • http://superbarter.sk/media/file/jugefami.pdfIn PDF document text
    • http://samsungdvm.net/upload/ckfinder/files/50061926954.pdfIn PDF document text
    • https://globalathena.com/ckfinder/userfiles/files/tifosisudovovufukidebone.pdfIn PDF document text
    • https://vanphongphamhienluong.com/upload/files/305994261.pdfIn PDF document text
    • http://vasset.bg/userfiles/file/govozobeduvowojitadelute.pdfIn PDF document text
    • https://madhubanindiancuisine.com/nbloom/fckuploads/file/43645167055.pdfIn PDF document text
    • http://xn--aknmedical-yub.com/uploads/file/pataxi.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/5c62756290b9cebb3efc832e8e191fc6/96967495944.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_off0000d566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD566 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED78 19316 bytes
SHA-256: 0becadef7cd5a235b37962bbf4c596c92fb7077dd204d62ebeeda37303bff15f
font_02_sfnt_off00011e8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E8E 10676 bytes
SHA-256: 9a95ec7856a2576eeab84266f9965e60979c9188cb453134b96f814988c53fd8