Malicious PDF — malware analysis report

Static analysis result for SHA-256 53d353633babaf8c…

MALICIOUS

PDF

83.5 KB Created: 2021-08-27 17:11:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b27e2175a8f5abc27f14d527e2f87c4d SHA-1: ce9baf638134ee0f91eb09f19f1eebf4a4be28d5 SHA-256: 53d353633babaf8ccef4b9cf61db35b20c43889b504957e134b61b749bb14d1a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate a link farm strategy, with a high ML score and ClamAV detection confirming malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are strongly indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://chcial.ru/uplcv?utm_term=confidence+interval+2+proportions
    • http://soul-program.com/clients/e/e8/e84723a0d254fbc5507aaa4bd1967541/File/29606958019.pdf
    • http://liburnia.pl/userfiles/file/votatakuzitapegufepo.pdf
    • http://vo23.ru/upload/file/34649473056.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/6d7215e10dfce0cf3f19513dd2a70082/49976115204.pdf
    • https://skywaytravelandholidays.com/ckfinder/userfiles/files/8651549778.pdf
    • http://legendtec-eg.com/wp-content/plugins/super-forms/uploads/php/files/sn7n8k917bocb55auo9u9gr9t2/21286220600.pdf
    • http://cheers-gifts.com/userfiles/loparuzexupupomidopafep.pdf
    • http://aiaato.com/FileData/ckfinder/files/20210704_DA21679FC4308073.pdf
    • http://bagumul.com/file_upload/spaw_upload/file/20210823195356.pdf
    • https://matrainagycsalados.hu/userfiles/file/74635773922.pdf
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/fa76f4a4d45557944075b61353559060/pelivufigasosakudukuwij.pdf
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/c2ae49fb177a1811cae9d2f9297b2fc8/wemazosevadilimax.pdf
    • https://area5srl.it/file/91704344768.pdf
    • http://unionzglobal.com/ckupload/files/98687401014.pdf
    • http://coinproject.com/userfiles/image/file/41687464232.pdf
    • http://alternatifmedikal.com/img/userfiles/files/87635608499.pdf
    • http://leasingtowers.com/ckfinder/userfiles/files/megutinefivi.pdf
    • http://www.sas.edu.mn/ckfinder/userfiles/files/soduwexozukonebo.pdf
    • http://burattinojatek.hu/userfiles/file/wamaxaritutib.pdf
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160778aa2215a9---wopubuv.pdf
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1606d62323d303---bitetopide.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/4f0ff7fcef91c469bb8ead9e49a57be4/wanarikiwib.pdf
    • https://flyingfish-stay.com/userfiles/file/21145614727.pdf
    • http://szentistvanpatika.hu/upload/file/wazixoravefowurerijefedis.pdf
    • http://engineersclasses4competition.com/files/others/feluvodadevebiwav.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dafa.bin
d5e25e8b34fca55f26446788d20bc1714bae8de2d548929103e96fb2698a62ed
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAFA 18892 bytes
font_01_sfnt_off00010c54.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C54 16792 bytes
font_02_sfnt_off0001246b.bin
c57a843c2a35eaa247f7f2ac3c491cdb1b830b5e884bb238a2ca14c2a4fb20a1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1246B 10832 bytes