Malicious PDF — malware analysis report

Static analysis result for SHA-256 a33e06cf161a664d…

MALICIOUS

PDF

85.9 KB Created: 2021-07-04 19:04:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 07550a2cbb30053b78d3405e09319cfe SHA-1: a08af1b766e1483ddc5b5401bd0e422bfb583418 SHA-256: a33e06cf161a664d26fd68871f05c400a0f9474b2568e3a0d8d8a5985f6f9c1e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Multiple heuristics identified the PDF as a link farm pointing to compromised CMS upload storage, suggesting it's used to host or distribute malicious content. The embedded URLs, particularly those hosted on compromised WordPress sites, are strong indicators of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160715bf37431c---77122998933.pdf In PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/rqqpgu9bh86fp2469u22p5f5rl/bijoli.pdfIn PDF document text
    • http://olympicburger1988.com/uploads/files/71527100899.pdfIn PDF document text
    • https://tipresentoio.it/images/file/66386367776.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/16091967eb5e45---57981862572.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/670379d41f48370a56b170dc86908145/29575839771.pdfIn PDF document text
    • https://pablohernandes.com/wp-content/plugins/super-forms/uploads/php/files/06c59a3898b524df4fa56252e10d5086/53366264343.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609848578b90f---23510766555.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/ef938c90f9c4d729d9a11d5455147f88/7970703509.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160738b975597f---57438415783.pdfIn PDF document text
    • https://gazelletr.com/userfiles/files/riburowewajibavusuwogi.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/92ff05ac9202eed9523eab43c3962f63/dukigilegupubigajajaga.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160850ab74acb7---piwigizavabejukuzawedo.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b59c474caaf---18251168373.pdfIn PDF document text
    • http://kapli74.ru/upload_picture/jujezoneredepumotodilu.pdfIn PDF document text
    • http://jamessham.com/admin/usercontent/file/12005542762.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16081825a5936b---rekewekanutilawasefaki.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/re50plakgb8943ibik7v0ssuo5/3056959876.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/a565458c5986b6458748749ab7133f99/rexapafinulufirimiv.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607b78db21352---pilexepowe.pdfIn PDF document text
    • https://mebelihome.ru/upload_picture/jumukabedat.pdfIn PDF document text
    • http://kirilmazbardak.com/userfiles/file/45702951666.pdfIn PDF document text
    • https://arket.io/wp-content/plugins/super-forms/uploads/php/files/524kat6mi3m5k1lir6kkcmbg42/55053457081.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/3f62298236edc313db0e18f14b98e8cd/37267880958.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be785d1e357---bexoputobezosefenew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=power+amplifier+questions+answers+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_off0000e9bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9BB 10992 bytes
SHA-256: 954e8b23e4d8f88717d1ed2ae67cc1dff43e1334f659de7928c20af5ddd4d68c
font_01_sfnt_off00010317.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10317 17900 bytes
SHA-256: d29e29ef0470e4108c41f7c71220bf46e86155606343d36c593d467c213efcfe
font_02_sfnt_off0001323a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1323A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1