Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf7c170f15569016…

MALICIOUS

PDF

77.9 KB Created: 2021-09-04 11:42:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 32d60274a3a46deab9379b8daf5c5b64 SHA-1: f30ccd8a6cfcb67a197e799915bb1f25959b1d01 SHA-256: bf7c170f15569016ac5efec8f1e8ade45bb9bafde8770d91edac46d82fde0dc2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF that contains numerous links to external websites, many of which are hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics suggests a tactic to obscure the true malicious destination by using link farms on disposable or compromised hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://crysiq.ru/uplcv?utm_term=biology+class+9+notes+pdf+download PDF link annotation
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ac685af92---panukerutememafitero.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16089c22f9ace4---76552055784.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/024278bc3cf8d63f2dd40555c5f5e551/4562966705.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16123c00cecba7---96226157058.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/5kadva4t6kr8sn1h05d8u8mfit/julotuw.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b98581581b0---12586468556.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/3862018944.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160988736327e9---kigukomubutumotixiwosova.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/8615877758.pdfIn PDF document text
    • http://unicaconsultoriarh.com/images/files/lorudokoratujelo.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a21ccbcd102---56042635477.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608750eb75fce---lagakozonigivijasibavi.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/dm9so4ufsiv7lgm5134seqorcn/pilirip.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9a837a224e---vifotojugoxuwe.pdfIn PDF document text
    • https://lawina-radom.pl/files/file/5337272449.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/uuk818jq2oo9o9uietnvcf1vm5/92549698323.pdfIn PDF document text
    • http://belv.ru/userfiles/file/dovezosozujozebofopinif.pdfIn PDF document text
    • http://learnazia.com/fck/imagesfile/93682133291.pdfIn PDF document text
    • http://glttek.com/userfiles/file/84647724060.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021626923258311.pdfIn PDF document text
    • https://globalazeri.az/wp-content/plugins/super-forms/uploads/php/files/l9a15mdg12uu1vpanniv53lhn4/torivotiku.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/280015267114.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/l7rl2h3d0g4ev8gl2i9v752136/morupetak.pdfIn PDF document text
    • https://nazragame.com/calisma2/files/uploads/24784239270.pdfIn PDF document text
    • http://s292376414.onlinehome.fr/datas/imgmail/file/tekutavawakike.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_off0000cb8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB8C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e3a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3A3 11116 bytes
SHA-256: 912c399d176f5e569576b943dccdde4ce46e4e0e1d1d17ba1b3ac088c9567e3b
font_02_sfnt_off0000fda3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDA3 17232 bytes
SHA-256: 7b2afb34ab25ce37a62bccc2b91be6b5169b691ecafc633a2872e0be779796d0