Malicious PDF — malware analysis report

Static analysis result for SHA-256 a898d57d85ed3b3c…

MALICIOUS

PDF

76.1 KB Created: 2021-07-09 01:59:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: feb9c3b53ff07cd553973c8babcad6bb SHA-1: 444cca77e2b9ac4134a3f9725b724e8b278f856e SHA-256: a898d57d85ed3b3c2a8fcb5eb13523a1fa351bcd0b5a74b9493670810dbd47c0
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress upload directories, indicating a link farm designed to redirect users to malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the heuristic findings point to a pattern of hosting malicious content on compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608236c1855be---76476700239.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070501c2ee67---sevizilezikuxevu.pdf
    • http://csc028.com/userfiles/file/20210611025330_3s9lsz.pdf
    • http://hutergroup.de/userfiles/file/25904966783.pdf
    • http://fulepmark.hu/nyebu/fulepmark/userfiles/file/geber.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609427184eb90---61552412172.pdf
    • https://vestol.bg/files/file/givipoveka.pdf
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160ae395474105---lekuvumejulowoluzin.pdf
    • https://agenciaboom.com/wp-content/plugins/super-forms/uploads/php/files/0k983qcugd91rddjlvpjmj1kg3/50897812839.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1607be760daf94---94571841834.pdf
    • http://amoy-art.com/Upload/file/18367467569.pdf
    • http://digjamaica.com/app/webroot/files/893355187.pdf
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf754446f2a---85386301420.pdf
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a8aebf69f33---67383424011.pdf
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/d11cbb25a60af07314480038a6df2b64/kosobeduge.pdf
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/5be722c2761863e04d037c9746879fe0/49472718723.pdf
    • https://gites-les-bardots.com/userfiles/file/luzalibidoselixima.pdf
    • http://memsports.com.br/admin/libs/ckeditor/ckfinder/files/68226876973.pdf
    • https://ebooksweb.net/files/file/lazakogokinafefazipebiv.pdf
    • http://blackhorsesc.pl/userfiles/file/pukinogajewofawun.pdf
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/25551200017.pdf
    • http://metabolit-plus.ru/files/file/8374668600.pdf
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16095926c5e18d---filowupovewa.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2812f68003---99396059148.pdf
    • http://ridendo.cz/files/file/58757679136.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=the+exiled+realm+of+arborea
    • 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_off0000c7e7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC7E7 16792 bytes
font_01_sfnt_off0000dffe.bin
095b66d01d8389d35c48110c55de58ba7a3532ab3fe42e07ddee4785126ab139
pdf-font-stream PDF embedded font (sfnt) at offset 0xDFFE 10452 bytes
font_02_sfnt_off0000f7a1.bin
56b21a5fd797673b319fec99bab1e48f8b1177f42ee8a1292653c21128e2545b
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A1 16544 bytes