Malicious PDF — malware analysis report

Static analysis result for SHA-256 a85c981edac9e93e…

MALICIOUS

PDF

73.2 KB Created: 2021-09-19 07:21:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5d035bd837ba2b520823377f41450c2f SHA-1: c8fb9b9da16d8e49d880f8b0d52df02f1b1d9806 SHA-256: a85c981edac9e93ea67fbcc675a6176ae8eefb9530429bf429ca8d00aceecb26
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs pointing to various websites, many of which appear to be compromised CMS uploads. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of link farming on disposable hosting, suggesting an attempt to direct users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://irlanc.ru/uplcv?utm_term=cannot+download+whatsapp+from+play+store
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8ce02ca17---25215233107.pdf
    • https://arhstroi.by/uploads/files/33641858341.pdf
    • http://graficaeformazione.it/userfiles/file/kafusufeso.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16142a6831042a---wexadofijaxutonoji.pdf
    • http://qianshunqs.com/admin/upload/riduratuporame.pdf
    • https://www.tratedu.net/ssss2018/assets/143ad273/ckfinder/core/connector/php/upload/userfiles/files/aa4f8e9afdf3f65f744f2ada41192045.pdf
    • http://playonathletics.com/userfiles/file/56705463148.pdf
    • http://steffis-strassladen.de/userfiles/file/lejusajokeweso.pdf
    • http://zh-huaxun.com/uploadfiles/files/kuxifavepaxa.pdf
    • https://stmarys-perthamboy.com/upload/File/18650208199.pdf
    • https://www.oalysa.cz/ckfinder/userfiles/files/kodulosemi.pdf
    • https://valubil.com/public/uploads/cms_file/cms_files/42333331900.pdf
    • http://huijingweb.com/upload_fck/file/2021-9-12/20210912225700796564.pdf
    • http://tweddlefoto.com/files_contenidos/upload/files/43879663019.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/5fds7aub452b16v4utfrumnpuj/31050638767.pdf
    • http://montoaneli.com/ckfinder/files/93547827295.pdf
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/161400d6e35c8d---zukesobironilibobilewos.pdf
    • https://hanakspotrebice.cz/eshop/ckfinder/userfiles/files/75031256763.pdf
    • https://optimuselearningschool.com/learning/site/images/uploadfiles/jatevilixuromejuvodozal.pdf
    • http://elitsatodorova.com/uploadfiles/file/figixaseto.pdf
    • https://quatcongnghieput.com/uploads/files/57924065559.pdf
    • http://tiszaladany.hu/upload/file/6184501796.pdf
    • http://hoteldarim.ir/basefile/hoteldarimir/files/19531738324.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bd10.bin
e882d381b57461a1d43eb05934e4a246355bd9540a970d15fd3bec56a12b1e15
pdf-font-stream PDF embedded font (sfnt) at offset 0xBD10 15840 bytes
font_01_sfnt_off0000e580.bin
e6f95ef59ce71e535cdcf193be9ee19b748a96d34dd506942737265d42851338
pdf-font-stream PDF embedded font (sfnt) at offset 0xE580 10904 bytes
font_02_sfnt_off0000feb1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEB1 16792 bytes