Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ef81aea6ba2e35…

MALICIOUS

PDF

83.5 KB Created: 2021-09-18 07:00:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d09189576086188fb33062db9c02a77e SHA-1: 87af5deec1c139833488646e4662fe2160b72734 SHA-256: 81ef81aea6ba2e35a305355ed98f714af70640df03b49d65582a24b2578f1820
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document is classified as malicious by ML and ClamAV, indicating a phishing or trojan-like behavior. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress uploads and disposable hosting sites. These links likely lead users to download malicious software or engage in phishing activities, such as the lure for 'windows movie maker for windows 10'. No scripts were extracted, but the PDF structure and URL patterns strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://nomylo.ru/uplcv?utm_term=windows+movie+maker+for+windows+10+64+bit+offline+installer PDF link annotation
    • http://huemin.com/fckeditor/userfiles/file/31018480828.pdfIn PDF document text
    • https://stancijanegrin.com/userfiles/file/37106237814.pdfIn PDF document text
    • http://savytrading.com/userfiles/file/sewivopitudukifuruku.pdfIn PDF document text
    • http://snp-ent.com/files/fckeditor/file/195368356613c13d482586.pdfIn PDF document text
    • http://sprostredkovanieuverov.sk/res/file/54940779454.pdfIn PDF document text
    • http://eachfun.com/ckfinder/userfiles/site_eachfun_com/files/kanuwetinujosadupakegatog.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133ae79513f9---vubobarijusexolusagutata.pdfIn PDF document text
    • http://zapatosperezcabrera.com/ckfinder/userfiles/files/29703652727.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/reruwalukuwev.pdfIn PDF document text
    • http://profstil.az/userfiles/file/51954490320.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614228c7be50e---77064154619.pdfIn PDF document text
    • http://shiokuda1.com/contents/files/kalawemozonasifudak.pdfIn PDF document text
    • https://conviviodihera.it/dati/upload/file/79867147440.pdfIn PDF document text
    • http://expnavi.com/sites/all/sites/default/files/file/sezowosomizonowilet.pdfIn PDF document text
    • http://obasekiestates.com/UserFiles/file/68344707472.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612f49d1497d9---8114186748.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613c05cd092e7---94064065894.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/jisunuj.pdfIn PDF document text
    • http://wimborst-ceramics.nl/public/view/upload/fckeditor_images/file/jeroduxoxisiva.pdfIn PDF document text
    • http://westpakusa.com/phpsites/vertical_living/uploads/file/56483260735.pdfIn PDF document text
    • https://copab.tn/216mag.svn/uploads/files/96629808076.pdfIn PDF document text
    • http://freewest.at/15841397855.pdfIn PDF document text
    • https://h16hr15k-h19hr37urn.com/contents/files/ganudinekod.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210905001027.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/fumavizug.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_off0000dd99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f5ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5AB 18456 bytes
SHA-256: 2c182e338de13fcc9b5357b76dd91633252700f937c006898bd9fc6a08191929
font_02_sfnt_off00012554.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12554 11312 bytes
SHA-256: 00a89ab56f16c1a1ba0fa8ae61915ddd7ec66ec9c696d0db7995c658e295cf50

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