Malicious PDF — malware analysis report

Static analysis result for SHA-256 771ec09e5bbac758…

MALICIOUS

PDF

73.2 KB Created: 2021-09-13 09:01:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 322555f6e67cd98a2ab7b44074a36056 SHA-1: cacb0d86a457ebfdf026ccd594e64c90532ac33c SHA-256: 771ec09e5bbac758d1f09bea4f4c3ae5f8e4b83cce0d6d011c1a47c04413b809
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. Heuristics indicate the presence of a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. While no scripts were explicitly extracted, the nature of the link farm and the PDF format itself often implies embedded JavaScript for redirection or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1613273ae9f50d---40472630627.pdf In PDF document text
    • http://inteko-tula.ru/f/file/remerajesizoxexuw.pdfIn PDF document text
    • http://murielbellhomes.com/userfiles/files/niwajibon.pdfIn PDF document text
    • https://vico-real-estate.com/ckfinder/userfiles/files/4387178330.pdfIn PDF document text
    • https://electroagro.es/pub/files/4692946440.pdfIn PDF document text
    • http://sdds.be/userfiles/file/50378615981.pdfIn PDF document text
    • https://pcetravel.com/files/file/nigufu.pdfIn PDF document text
    • http://chpcentre.com/files/file/49472457237.pdfIn PDF document text
    • https://nangluongvada.com/uploads/files/52796142397.pdfIn PDF document text
    • http://dautuck.com/uploads/userfiles/file/79188936135.pdfIn PDF document text
    • http://siamsnail.com/media/userfiles/files/pemurujisilimo.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/214f287138c37b3e4c9a944f43330817/sipisasutavibex.pdfIn PDF document text
    • https://taxfirma.com/userfiles/file/8039828041.pdfIn PDF document text
    • http://fulepmark.hu/nyebu/fulepmark/userfiles/file/63745294148.pdfIn PDF document text
    • http://kirakuramenandsushi.com/uploads/files/fewigowo.pdfIn PDF document text
    • http://szm.hu/userfiles/file/46491324295.pdfIn PDF document text
    • http://smm-mm.com/uploads/news_file/11736816886.pdfIn PDF document text
    • http://sofar-france.com/userfiles/file/xiridavow.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161313c9589b6e---56893215786.pdfIn PDF document text
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1613eddb9ae624---15145854899.pdfIn PDF document text
    • https://huangs.tw/uploads/files/202109110506598372.pdfIn PDF document text
    • http://miryangpension.com/FileData/ckfinder/files/20210901_EF4103F05B309471.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613c65836679c---1659240530.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=how+to+recover+deleted+images+from+mobilePDF 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_off0000bbfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d414.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD414 10996 bytes
SHA-256: 791e63212944e9e636f70e96ce96d90eae380e1a1a270f22aff8cdc3d67bda84
font_02_sfnt_off0000ed7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED7A 16068 bytes
SHA-256: e0784628a520075007b9eac7bd4936da06c3f517664c1001e764df5994a47873