Malicious PDF — malware analysis report

Static analysis result for SHA-256 23c5336c59ae1a87…

MALICIOUS

PDF

78.3 KB Created: 2021-09-04 13:12:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 5bcb0f52be9305b06b14cb6adf375a89 SHA-1: 048edf35d2190da7e45556408db9ccbf00fb0d21 SHA-256: 23c5336c59ae1a87e6d986e83b2c4aedbb5740862dd1ff9866534516d3eaac0f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are identified as compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded URLs suggest a tactic of directing users to malicious content hosted on potentially compromised legitimate sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/577e73dd88d22b0c490461c69173c30c/radovuwaberepexoriba.pdf In PDF document text
    • http://phuocthuan.vn/images/pic/file/bobamedatas.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2f9745891c---81955233880.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609804747b489---lezelixemariwefoduliwobun.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/28365456159.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/fupimimolekurib.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/58bacadd7ca071adaa9ff62e32e9df29/zulimiduwibogeloruk.pdfIn PDF document text
    • http://hanboo.cn/Uploads/file/2021062910513570554.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1ac500e2ac---42115135429.pdfIn PDF document text
    • http://xn--h49al33a2zdp0eo1x.com/DATA/file/20210705131417.pdfIn PDF document text
    • http://wasserburg.pl/userfiles/file/fagebilavago.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/gbic6atva2ro1mela8v16e8dt0/ranududitiwenesadoje.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160afdac6483bc---kufaludes.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/00m3r3ir7tp12e7iftot8eie7p/vusuzexurunam.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/69531108977.pdfIn PDF document text
    • http://acm-medicali.it/userfiles/files/17806331708.pdfIn PDF document text
    • http://abogarestudio.com/userfiles/file/zijugikumojed.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/b48385e112a729fc4c69692444e4289b/xugodejibeziz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=convert+png+file+to+pdf+formatPDF 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_off0000ce7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE7B 17628 bytes
SHA-256: 47646053b0b7577cca49c1f63ba53190fff53a13d1fee87c585154b69d7dbc66
font_01_sfnt_off0000fbaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBAA 10768 bytes
SHA-256: ac015100986cdc97ed5d9ee9e2d45b60ea61c3de5205ac9d30f72a15a34fa306
font_02_sfnt_off0001143e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1143E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1