Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4ebd15ab9ed515a…

MALICIOUS

PDF

77.5 KB Created: 2021-09-13 00:14:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1f25e18bade7a9412528aa6c0e26ef92 SHA-1: 1bcd2a82079ab41eb3f273325e5e0b73a17d7662 SHA-256: a4ebd15ab9ed515a7d60c5c5ae4055f9a1e496159cfcf3aaa54e3189562a2b6b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains a link farm pointing to various compromised websites and disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of external URIs and link farms indicates a likely phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://nhasachnguyenvancu.com/Images_upload/files/36007156967.pdf In PDF document text
    • http://kystar.net/filespath/files/20210907072513.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/41bb4a4e0853429dd21a85ece2b51b8f/13546142613.pdfIn PDF document text
    • https://podiummagazinenews.com/ckfinder/userfiles/files/fawuposotogefazadiboxo.pdfIn PDF document text
    • http://blessingsngo.in/userfiles/files/53145065127.pdfIn PDF document text
    • http://sxnqx.org/upload/file/Fl202109030508113751.pdfIn PDF document text
    • http://okuninka-biale.pl/userfiles/file/fajakuvubateguni.pdfIn PDF document text
    • http://showdoimovel.com/files/files/46418375041.pdfIn PDF document text
    • http://teresachild.com/upload/files/28366457485.pdfIn PDF document text
    • http://kosmonautika.ee/ckfinder/userfiles/files/werutefadajuwi.pdfIn PDF document text
    • http://aurora-c.jp/files/files/63778985845.pdfIn PDF document text
    • http://maxidmum.com/images/upload/fck/file/tumuwatepunivuku.pdfIn PDF document text
    • http://hardiebase.com/uploads/assets/filefile/wowob.pdfIn PDF document text
    • http://angel-conference.org/upload_fck/file/2021-9-12/20210912015345146997.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e47b0edb7c---buzidarupimuwetopoze.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6af5a31dd---21345839421.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/1qn2r9do8hm605a40412t2c0oq/70544915860.pdfIn PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210909140915.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/ruzitojifawapona.pdfIn PDF document text
    • https://natyabio.com/uploadfiles/1574896161.pdfIn PDF document text
    • http://ei-windykacja.pl/upload/file/zitegiz.pdfIn PDF document text
    • https://hotararicedo.ro/files/files/39854265720.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=poco+x3+keeps+restartingPDF 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_off0000c8d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8D1 10868 bytes
SHA-256: 291642a46cb400b8c2e18b1bef0dccbeb5e628293d2391b9cd36febfc1f04b80
font_01_sfnt_off0000e230.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE230 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA42 17840 bytes
SHA-256: 4b9edce5ca49011e87b37ff70b173ed52caca53a206f80cc580f5068a841ce80