Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1f3d052b3d40043…

MALICIOUS

PDF

79.3 KB Created: 2021-09-21 01:20:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b5c01033facddf88c481c1c0466e6ba9 SHA-1: 8d1c91776f3a1001ab3e1ee22eb16e519e8f1e4a SHA-256: a1f3d052b3d40043982e84b5e8383d1e15e1f7c6c3595d849207ef364fe99b0b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and link farm heuristics points to the primary attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 https://coretry.ru/uplcv?utm_term=overdrive+2+mod+apk PDF link annotation
    • http://aedelsur.com/contenido/files/52992160830.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/9q94es5qt13s3tps6b0ropmnv6/xabodazowopolezajugevixa.pdfIn PDF document text
    • http://cjpharmtech.com/upload/files/vumopusawakofaxiwenupil.pdfIn PDF document text
    • http://cukiernia.eu/upload/files/zenevorozal.pdfIn PDF document text
    • https://servicepapik.ro/files/wigerusijef.pdfIn PDF document text
    • http://gr-chem.com/upload/files/60156721758.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7e2922926---39088132407.pdfIn PDF document text
    • http://lovesenergy.com/file/24444412803.pdfIn PDF document text
    • http://studioguidobarbieri.it/userfiles/files/nejel.pdfIn PDF document text
    • https://karlholmbygg.se/UserFiles/files/90487007112.pdfIn PDF document text
    • http://azizolace.cz/images/file/34265832044.pdfIn PDF document text
    • http://umhouses.com/uploads/files/34008350343.pdfIn PDF document text
    • https://projektovanje.info/userfiles/file/temabulegumalone.pdfIn PDF document text
    • https://lifo-sea.com/ckfinder/userfiles/files/92812830733.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/tbipkv23vnftkv1loi5a50rio2/43428962476.pdfIn PDF document text
    • http://taxilitomerice.cz/ckfinder/userfiles/files/47105056713.pdfIn PDF document text
    • https://astefin.ro/ckfinder/userfiles/files/piwiwivegekewupesuzaj.pdfIn PDF document text
    • http://escrima-rlp.de/userfiles/file/xazozomigagaxamimevip.pdfIn PDF document text
    • http://bubb.cn/up_file/file/diberudububixeziwozes.pdfIn PDF document text
    • http://gaudi.tw/upload/files/51833740543.pdfIn PDF document text
    • http://telektrans.hu/editor_up/dizakuvebawodet.pdfIn PDF document text
    • https://budapestpainter.hu/ckfinder/userfiles/files/tatunemaxe.pdfIn PDF document text
    • https://ssekolkata.com/ckfinder/userfiles/files/89441692968.pdfIn PDF document text
    • 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_off0000cf59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF59 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e770.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE770 10440 bytes
SHA-256: 3911c7799397f1c4e77f430fcb0796911913113eb75567dd91bb910a3b6bdbdf
font_02_sfnt_off0000ff2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF2C 18600 bytes
SHA-256: 1c6a9591554592ab4f217a81ce4ffb4b8458354e35882de21b048f4e024b7bd2