Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b73b5ba4ffc730…

MALICIOUS

PDF

82.0 KB Created: 2021-08-29 05:12:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 518a2df2a0eddfc48e75cbfd574c0bef SHA-1: 0dd7f55a8eddf5fa180423b41cd8407caadfb7d9 SHA-256: 21b73b5ba4ffc730b94a194143e87d14e1f8a53ff57824276e69c25a9cfef3c8
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites, suggesting a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://laborke.ru/uplcv?utm_term=mechanics+of+materials+beer+and+johnston+7th+edition+pdf
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/makinuperokobi.pdf
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ccd3b65180---20950712637.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/161203d9e803fa---38898150508.pdf
    • http://aarogyamedico.com/userfiles/file/54367392721.pdf
    • http://www.saito-ken.jp/userdata/file/refizi.pdf
    • http://accronline.com/userfiles/file/juroled.pdf
    • https://solener.info/ckfinder/userfiles/files/tawatuxukolomiruboba.pdf
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/e2b02f38db2694eda508d7a2579a8aa3/vuvazawoxofakowej.pdf
    • https://aldwalia.com/userfiles/files/66040535246.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b9d94598204---sepururutepumaz.pdf
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160a8119fa6374---nitanodekikeluludolaro.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1610c33f1ab09f---12254290476.pdf
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607e92e2f17a1---rovodamefaruvasegasek.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/505d2f6512f585af4452d4c8890aae3b/setotolo.pdf
    • http://irths.com/upload_files/files/78502039446.pdf
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/seforubisur.pdf
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/pupkvl4i6bn5pddtm1s8ih9kq6/lezajanisew.pdf
    • https://organicfertilizerproduction.com/d/files/zilurimaxuwonixifodux.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160975698e48c5---buwenifinitebulodeborepeg.pdf
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/ad0e9ee24f89ab5297f719a9da7707bf/26210948752.pdf
    • http://decamiones.com/userfiles/file/37065417406.pdf
    • https://kuzeyilac.com/resimler/files/11567421047.pdf
    • https://saatyapi.com/upload/ckfinder/files/22478508306.pdf
    • http://yuss.it/file/91002904024.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_off0000cff1.bin
c11af8c2536e626381ac41df54ac8469dc4bb4f72c6f7b23cfd58e03fd4fe9cb
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFF1 11196 bytes
font_01_sfnt_off0000e9b3.bin
835b48a34f6666ed40d23e11a1b30c0e074872c6a5f8182c4c414a52aa36d354
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9B3 21400 bytes
font_02_sfnt_off0001207a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1207A 16792 bytes