Malicious PDF — malware analysis report

Static analysis result for SHA-256 28b1cecdd249292e…

MALICIOUS

PDF

97.5 KB Created: 2021-08-10 22:28:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 16e9bec5f5bfe790ea6ff66d0af26b13 SHA-1: e37ec343e32f2cd4f57a5db7fafc06022d42a430 SHA-256: 28b1cecdd249292e09ae04439aaff4ec93ce8fe55d8a5983473ae685f586f906
156 Risk Score

Malware Insights

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

The PDF 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, with numerous URLs pointing to potentially compromised WordPress upload directories and disposable hosting. The embedded URLs suggest an attempt to direct users to external, untrusted sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://uzunlarpeynir.com/dursun/upload/files/kifolisadezugefirufafunep.pdf In PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ce565e19ba6---tunim.pdfIn PDF document text
    • https://kildevangen.dk/files/bewegujivudapamugu.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/cdfbgola82sgh1g7f7oog47gih/kakepevodosulewevedijel.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/wabor.pdfIn PDF document text
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/g65m3o216370meamgp24rddrv9/60853075523.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/5a53a9a329801a7cf92acd774ad54948/95809023702.pdfIn PDF document text
    • https://alyansdugunsalonu.com/userfiles/files/dekodisazawekitugidapifew.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/3puo36rv36tip5vjhaj3e2sd46/fomakumugurizi.pdfIn PDF document text
    • http://sartor.ru/upload/files/fifejumu.pdfIn PDF document text
    • http://wenxuezj.com/images/File/99980836577.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/72516879676.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/020803307115.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160a1dce50e8cc---futolivadibelosozizenuta.pdfIn PDF document text
    • http://wedding-ideas.ru/ckfinder/userfiles/files/19723857387.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/83046691371.pdfIn PDF document text
    • https://glbtrader.com/userfiles/file/firurefax.pdfIn PDF document text
    • http://mirandatutoringcentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607d87d38b71e---mobep.pdfIn PDF document text
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/cc7d7a5e5c02f95ab521cc4aa2c1f6ef/kopabopusuvirujem.pdfIn PDF document text
    • https://www.sacda.org/wp-content/plugins/super-forms/uploads/php/files/9i2g802ihk7ba4qst7b0act0i3/55736935228.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c90e121eb9---sixuxama.pdfIn PDF document text
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16089e4ce57dfa---xojumererete.pdfIn PDF document text
    • https://bravo-hk.com/userfiles/file/9327165934.pdfIn PDF document text
    • http://osmed.cz/app/webroot/files/files/76447677519.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=warhammer+40k+space+wolves+codex+8th+edition+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_off00011504.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11504 11632 bytes
SHA-256: 6fc74640c404ff9f57078cc45af16029c55b1602b91c62cbb5a64db480240830
font_01_sfnt_off00013099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13099 17624 bytes
SHA-256: dbe23a3fabd1934997ef8f08d361dac34f2511c34fae41bc396b4649edb3a0bf
font_02_sfnt_off00015e73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E73 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1