Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf8737617a67bb70…

MALICIOUS

PDF

85.1 KB Created: 2021-09-21 21:35:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a36cdff03b242b95df536860cd085905 SHA-1: 064a03b6878d1cfff6202e673fabe3318161361d SHA-256: bf8737617a67bb7079ad7008c4b82f4765b83acc9de5f5577f54b9151227fa2c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to disposable domains and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' directly supports the finding of a link farm designed for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://zeminyerkaplama.com/upload/ckfinder/files/5152486675.pdf In PDF document text
    • http://snap-drone.com/userfiles/file/zibasowe.pdfIn PDF document text
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/gaseruvafebinef.pdfIn PDF document text
    • http://jubileejec.com/userfiles/files/46744276505.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/nusexigowuneworijur.pdfIn PDF document text
    • https://testagenda1.myagenda.cz/pictures/editor/files/zeripowavin.pdfIn PDF document text
    • https://slavicchurchmississauga.com/fck_upload/file/35645439601.pdfIn PDF document text
    • https://greenboo.vn/uploads/files/87950978592.pdfIn PDF document text
    • https://xn--90ah6akb9e.xn--p1ai/f/file/8854924798.pdfIn PDF document text
    • https://astoraccessories.com/uploads/ckfinder/files/dijagarenedafado.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/jitojapenive.pdfIn PDF document text
    • http://lnyuanzong.com/uploads/files/20210921093418.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/14068480122.pdfIn PDF document text
    • http://huyndaicaudien.com/upload/files/54938839955.pdfIn PDF document text
    • http://naturenhuman.com/app/webroot/userfiles/file/11549738084.pdfIn PDF document text
    • http://sabaispa.net/userfiles/file/tetubutagagazalaxel.pdfIn PDF document text
    • http://komodovo.ru/upload_picture/64326977770.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614218c9962d8---sabalunirosazet.pdfIn PDF document text
    • http://m3hotels.com/userfiles/file/zajudafuzowa.pdfIn PDF document text
    • https://coebmsf.com/userfiles/file/46688000853.pdfIn PDF document text
    • http://abwingscolley.com/uploads/files/53344088439.pdfIn PDF document text
    • http://studioassociatoemc.com/userfiles/files/sunezemaresabalotetag.pdfIn PDF document text
    • http://nghiencuuykhoa.com/uploads/userfiles/file/benuzudetujonowa.pdfIn PDF document text
    • https://promobryansk.ru/userfiles/files/zakapofamosawelefapi.pdfIn PDF document text
    • http://colokit.thienlonggroup.com/Images_upload/files/nenidegula.pdfIn PDF document text
    • http://rydelko.eu/userfiles/file/15484681041.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=take+a+screenshot+on+an+android+phonePDF 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_off0000e85c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE85C 17620 bytes
SHA-256: 0252387c94cdcb32e9144e2df2c3960100477e836d14ad7d609dc9ba92efc7b6
font_01_sfnt_off00011677.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11677 10620 bytes
SHA-256: ffb7b044a94779ccbb23ab249beb8f993d000071beabe774b39383c02dc2c02a
font_02_sfnt_off00012ebf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EBF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1