Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bc51512cc8da99e…

MALICIOUS

PDF

85.4 KB Created: 2021-06-26 16:38:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0443d9482dffd16d1f17287e8902162b SHA-1: 0298d37fe1b7eafba0b40d1c55a4e9c023fbec25 SHA-256: 5bc51512cc8da99e91562314dbaf626d6d40e3df6332f852be9af9bd9414c74a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to distribute malware or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://inwebjor.ru/uplcv?utm_term=biological+science+7th+edition+pdf
    • http://ozari-ua.com/files/file/18486291611.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/b036ab24b54e728b0d3f516fd033dae6/11250980078.pdf
    • http://fernandopelosini.it/userfiles/files/zefaxa.pdf
    • http://donghozibistore.com/luutru/files/bilobojagipug.pdf
    • https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/9d4emmka94o30om76e6ceh3oi2/87520619739.pdf
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/73bde06a62aac9f58a43a9534722225d/fexabarutow.pdf
    • https://advantagelic.com/singhania/downloads/file/79304161263.pdf
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/84440742520.pdf
    • http://angeladaniel.eu/uploads/files/58243690924.pdf
    • https://nutricionintravenosa.com/wp-content/plugins/super-forms/uploads/php/files/1ff3ac8f15d86152d4321049f396469d/nuxajupudadamud.pdf
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16086239ef23d0---89787497368.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a684a727f22---ribuwadagodavobilozikijet.pdf
    • http://momsystem.ru/public/file/17625465452.pdf
    • http://anhuizhkj.com/upload_fck/file/2021-5-22/20210522182820683353.pdf
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c0060eeb394---85003499951.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2d0aa8c04---juwagapadozipuru.pdf
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/inh33j3vfegvlq88e38166ri3h/bubinar.pdf
    • http://lucann.com/Upload/file/koxixasevikipa.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/9e17e56bf82e0fe3aa58b1717759f54c/54184886891.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_off0000e8e3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E3 16792 bytes
font_01_sfnt_off000100fa.bin
32d14bf9eba63a0fc727a14583d772fb3173593e823f9cc732175e1fd5143158
pdf-font-stream PDF embedded font (sfnt) at offset 0x100FA 10904 bytes
font_02_sfnt_off00011a04.bin
e642f27ffa8fec1c1f81367564d34ee093b8d379ec812d843b08493d304df864
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A04 17888 bytes