Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8c40d567dab8f62…

MALICIOUS

PDF

87.5 KB Created: 2021-08-16 00:17:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dcdaeb9e2cdc4a43a71de5bc3407b595 SHA-1: a5320a470fde2552ef68504f060d9dfd9e2848ca SHA-256: c8c40d567dab8f629f2433bc3891a047aac6d467fb82f7488e94a2fa0412e9db
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains a link farm with numerous URLs pointing to compromised WordPress sites and disposable hosting, suggesting an attempt to lure users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://wastran.ru/uplcv?utm_term=why+is+the+red+standby+light+flashing+on+my+tv+samsung
    • https://vansuloi.com/uploads/userfiles/file/45370844899.pdf
    • http://websurin.net/UserFiles/File/zarogunolexozuni.pdf
    • http://email-database.info/userfiles/file/97303202066.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609ffe00d51fd---21534154489.pdf
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/a1bb9677a717293b80a9eb4d71ec0ca6/powelipijuluvunu.pdf
    • http://brixtontaxi.com/survey/userfiles/files/suzatamuxameduja.pdf
    • http://skoleniridicubrno.cz/ckfinder/userfiles/files/funazugunetisiroti.pdf
    • http://tpdw.pl/userfiles/file/dopamefovaxutozi.pdf
    • http://bioident.pl/photos_fck/file/19058721735.pdf
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/00ed8da639c067aeae3291da83815b02/34674264115.pdf
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/2c2a4c7044cc9c211af554c339f7c60c/gigadirejokobux.pdf
    • http://www.awakohchang.com/image/upload/File/ujisosazin.pdf
    • http://vitalenzyme.com/uploads/fckupload/file/41833290377.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c969d0650---5356374397.pdf
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/morubolevoxipalerolus.pdf
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/s4i65hevehuo24eiv86tjhj1q2/fogidotuwenudolo.pdf
    • http://xn----dtbhwhggdaoqfh3d.xn--p1ai/media/file/86671940817.pdf
    • http://travelshops.pl/userfiles/file/rijikenetu.pdf
    • http://densayhongngoai.com/uploads/userfiles/file/jojaroloxifotavevexixugok.pdf
    • http://carroll1975.com/clients/4/4e/4e2b018d07aaa5a30c3e4fca1c7a8df7/File/35986645977.pdf
    • https://pui-vital.ro/msg_media/file/40226238974.pdf
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/e79840a11e4ca6317c459a931480c49d/fokirinokoludoloruwe.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_off0000f266.bin
0248452b7a88088073c4707e492d312a7a949a7fc260ce3c126bacdbb1519508
pdf-font-stream PDF embedded font (sfnt) at offset 0xF266 16432 bytes
font_01_sfnt_off00011cbd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CBD 16792 bytes
font_02_sfnt_off000134d4.bin
b6876a7ce5881819649e8cd96e3d24b9733a10023fedaa144c8acf00ab82861b
pdf-font-stream PDF embedded font (sfnt) at offset 0x134D4 11212 bytes