Malicious PDF — malware analysis report

Static analysis result for SHA-256 5aaa36f345e585bc…

MALICIOUS

PDF

100.3 KB Created: 2021-06-27 11:41:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 43be6a894197194cef37de60add78a7b SHA-1: 5d26f97c3c5e7a05666dd4d8ed3309c7e331e938 SHA-256: 5aaa36f345e585bc2aec5c8fe4b2488765ab21ae8a0b10830a89c5d8f7772226
96 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to domains identified as compromised CMS uploads or disposable hosting. The ML classifier strongly indicated maliciousness. While no scripts were extracted, the structure and URL patterns suggest a malicious intent, likely to redirect users to malicious sites or for SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

Heuristics 5

  • 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 http://stringquartet.biz/web/images/fck/file/jelemo.pdf In PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/bg2p2ccfjvnv6q2qttr2v5vs0s/21998897634.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608042c8d6cdd---gijisonigibib.pdfIn PDF document text
    • http://shelton1961.com/clients/35589/File/bujalirepedupefejoj.pdfIn PDF document text
    • https://healthmatters.me/userfiles/file/9145258815.pdfIn PDF document text
    • http://pechati-piter.ru/userfiles/file/wukegolobujixuru.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609471b9a7aa8---15479627300.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/8b70c2f50caa3381e04a098e5bb5eb0b/nipud.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a04184d15e4---nuxitowe.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/87462981341.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/60h9205k7fdd6k78m8bohpn9m5/17319057063.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16083b2bcdb5fa---87670959688.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a5e9a79f86b---zizexanas.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160b0db724f2a0---9188339476.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/4mbgip48pto6v1olfnt1pkve41/71346205548.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/ninedupof.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/997526da0ff66ee99a4b54ff011fbee5/13152303513.pdfIn PDF document text
    • http://boothbayharborshipyard.com/userfiles/file/76404038458.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c887059bdaa---sokegabizokuwozukozuserus.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a82579cab3---vasifuduvopose.pdfIn PDF document text
    • http://aj-logistics.com/stock/userfiles/file/121534169.pdfIn PDF document text
    • https://profix.fr/ckfinder/userfiles/files/85896093487.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/75ec53b723e17c274d443247c133f478/9053729372.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=explain+the+barriers+of+communication+in+detailPDF 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_off000125bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013dd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DD1 16912 bytes
SHA-256: c8aa6431f75007e575ca555eb3631d3626791f1ee20e12bdb19acc543460db96
font_02_sfnt_off000169e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x169E9 11208 bytes
SHA-256: 35062c1c17bdf669edc56f1540cd752142865933a72920bc785b5e3ddda5bea6