Malicious PDF — malware analysis report

Static analysis result for SHA-256 91e33524c95e4daa…

MALICIOUS

PDF

74.9 KB Created: 2021-09-06 18:30:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 67ec85df720405f3cd13572a4b4c0ab1 SHA-1: 3dd82051d92534611df172683cdddc1c2a0d2e7f SHA-256: 91e33524c95e4daa49a4bf4c73d20de49f81e5ed87da169f59fea7d947ed4850
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload directories, suggesting a phishing or malware distribution lure. The PDF structure and numerous external links, many hosted on potentially disposable domains, support this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/m6u2h03du5nqstvgqubmmhkic1/11684489990.pdf In PDF document text
    • http://shinaval.ru/userfiles/file/16065549931.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160818db13bb26---xuzegi.pdfIn PDF document text
    • http://scpt.it/userfiles/files/terenozu.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/jalubasem.pdfIn PDF document text
    • http://isystemlab.com/admin/ckfinder/userfiles/files/72826528643.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/60767977731.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/qqj31kv2107aie1dl4o7fla7cf/18728872824.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/3f39e83da7b034c20b511a0bfb0a4be7/74323681726.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/fitudigidepij.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vareritigi.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/1167f3bb545c4ffbf3768730ebcbb6ba/wosotipisopixipi.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160ec989db3540---lipuwafemawobomulil.pdfIn PDF document text
    • http://songiadahoaian.com/upload/ck/files/97887418502.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609da7252fab4---nuxakemodi.pdfIn PDF document text
    • http://barrospizzadb.com/uploads/files/11718300861.pdfIn PDF document text
    • http://www.smartlandgroup.com//ckfinder/userfiles/files/paxotonu.pdfIn PDF document text
    • http://olneyjune65.com/clients/d/dc/dcef5d22f85ec69f5810ba62c2e8cf46/File/jukeji.pdfIn PDF document text
    • http://stitesattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/57894807042.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160768b5cc840c---53054988995.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160706f1c5c9e0---gafijimunekes.pdfIn PDF document text
    • http://dermatologomiguelgallego.com/miguel/fck/file/47660891645.pdfIn PDF document text
    • http://bygreenpure.com/userfiles/file/fusobukugusigatufovuxisaj.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8a987e6355---jebamirepupufutu.pdfIn PDF document text
    • http://traviet36.com/upload/files/buwuvumowukateva.pdfIn PDF document text
    • http://dongtienlamnghiep.com/upload/file/mujevopudaxopekapepivujup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=apache+mapreduce+tutorial+pdfPDF 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_off0000c250.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC250 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA62 16420 bytes
SHA-256: d0f98a7b7bb52f34a290854d1da1fbe00a62d0cd4bf9826e6ecc9e838a149233
font_02_sfnt_off000104bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104BC 10692 bytes
SHA-256: 162d4196ead2edca95d442babe964a4f9b317c90aaa3ffcd580bc12d671f3ec7