Malicious PDF — malware analysis report

Static analysis result for SHA-256 51be376800da52de…

MALICIOUS

PDF

74.8 KB Created: 2021-09-10 02:54:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0d48db724ea7c64c951bbae4f3bdfba3 SHA-1: 3ecdf6801388e4c46bbd919ecc04535f1e99507a SHA-256: 51be376800da52de62171d3f0fdd98f07a181eea78813c325608621df06cc08a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to potentially compromised WordPress upload directories and disposable hosting sites, suggesting an attempt to host and distribute malicious content. The presence of a visual download button further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://ptaki.info/imgekoprojekty/files/zaniladepananipajepon.pdf In PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/fod9ji822frv36mekaelmd8da2/93326322901.pdfIn PDF document text
    • http://easy-sleep24.de/shop/images/editorfiles/file/86168567405.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/161374973c9483---76199545297.pdfIn PDF document text
    • http://studiogeologicotrilobite.com/userfiles/files/27476817281.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/53605491239.pdfIn PDF document text
    • http://chrisdepanneservices.fr/Sites/cds/files/xukavilefeg.pdfIn PDF document text
    • https://loonbedrijfschimmel.nl/userfiles/files/kefafezagozelukumobikodum.pdfIn PDF document text
    • http://abwgulfport.com/uploads/files/40568261997.pdfIn PDF document text
    • https://fundacjaartfreeart.pl/userfiles/file/89364009417.pdfIn PDF document text
    • https://derey.nl/app/webroot/files/userfiles/files/wisipajewomatomawokosa.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/beweruxupumukogob.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/79889832573.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/161382ebdab2db---vibebovabo.pdfIn PDF document text
    • http://talesma.com/E/file/67085903108.pdfIn PDF document text
    • https://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/63645971405.pdfIn PDF document text
    • http://shiokuda1.com/contents/files/72331665118.pdfIn PDF document text
    • https://www.bramfordgc.co.uk/ckfinder/userfiles/files/fukixafukenilifot.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/14660183598.pdfIn PDF document text
    • http://urs-certification.com/gais/image/file/39798499426.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd5fd15c19---51192214637.pdfIn PDF document text
    • https://millersexpress.com/userfiles/file/sesuna.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=midnight+club+3+dub+edition+remix+download+for+androidPDF link annotation
    • 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_off0000bef8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEF8 16792 bytes
SHA-256: 8cd06c91505b37e1c1f0ab60e7fadda554c8d38f1fb5dfcf83033cbd7d1d35c6
font_01_sfnt_off0000ea75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA75 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001028c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1028C 11348 bytes
SHA-256: e97684fd13c3776270a8376a09d257f038aca71b10d2646f5dfa78c04560b741