Malicious PDF — malware analysis report

Static analysis result for SHA-256 b52919182074f2cc…

MALICIOUS

PDF

70.1 KB Created: 2021-09-27 05:32:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e90556a6f453e8b6ddf1dbea16d70d8b SHA-1: 2cfaad37f5488f299cacd420233b781e5460261c SHA-256: b52919182074f2ccf72ffa33d852824b5ef4236c75eed7d588a3536030720343
146 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier. Heuristics indicate a malformed exploit stream, suggesting it attempts to exploit a vulnerability for client execution. The presence of numerous external URIs, many pointing to PDF files on various domains, indicates a likely phishing or credential harvesting attempt, potentially serving as a lure for a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://markmont.eu/editor_uploads/system/files/66764668436.pdf In PDF document text
    • http://lionsmarsala.it/userfiles/files/metuxima.pdfIn PDF document text
    • https://csam-villepinte.org/uploads/images/file/98353224118.pdfIn PDF document text
    • https://pestresolution.pt/site/upload/file/xudutijaso.pdfIn PDF document text
    • http://tysons-cafe.com/uploads/files/41789576346.pdfIn PDF document text
    • http://jiducn.com/userfiles/aa/file///45666272246.pdfIn PDF document text
    • https://ka-base.no/images_content/file/deradewo.pdfIn PDF document text
    • https://ladangmimpi2.com/contents/files/59362786808.pdfIn PDF document text
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/e9c31055cabc6315dce72b4dad2b4427/budelegibemulur.pdfIn PDF document text
    • http://shijijiaming.net/filespath/files/20210901212452.pdfIn PDF document text
    • https://moulindelarroque.com/userfiles/file/faxenogijejawivatisip.pdfIn PDF document text
    • http://www.iece.in/userfiles/file/xebinanubunorasugug.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/97439029061.pdfIn PDF document text
    • http://duetsepolno.pl/userfiles/file/jozivor.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/27ea078c6729c4305c0951b2000d1a99/serizugebi.pdfIn PDF document text
    • http://tano-cable.com/d/files/pexetusikurewomimuturexaf.pdfIn PDF document text
    • https://voyageaventurenepal.com/upload/files/96430651137.pdfIn PDF document text
    • http://luluscafeonline.com/uploads/files/61716900677.pdfIn PDF document text
    • http://jowinbio.com/upload/files/202109170825581569.pdfIn PDF document text
    • http://labellebeaute.com.hk/ckfinder/userfiles/files/meridemimunolim.pdfIn PDF document text
    • https://karlschool.org/uploads/files/202109140456126082.pdfIn PDF document text
    • https://ip-pharma.net/data/files/8180135970.pdfIn PDF document text
    • http://tobn56.com/UpFiles/file/46361847981.pdfIn PDF document text
    • http://tlumacz-francuskiego.pl/userfiles/file/30521563335.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/nefudonesakul.pdfIn PDF document text
    • https://www.totspotdaynursery.co.uk/ckfinder/userfiles/files/77928373866.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=bios+file+for+ps2+emulator+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_off0000b371.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB371 10932 bytes
SHA-256: 1fcd2f25cb319ced7fac92e53c33307b1dfc3451b0ef31177597dbc7ea2229e3
font_01_sfnt_off0000ccd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCD7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e4e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4E9 14748 bytes
SHA-256: 3b8a7f53f3e1b3e34fd5c7e7f6277e57658852e26c879ea843ad42a88892b264