Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5d51f7f5f2c4eca…

MALICIOUS

PDF

92.0 KB Created: 2021-06-26 03:27:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bbe25296dc5ce2fdc6ae831a7a42421b SHA-1: 3ed34b216d619141c906ca08bf14bff72ece39ce SHA-256: a5d51f7f5f2c4ecacf46c322c3786005b7ad74bfdb1a54c3376100230bcb2256
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to compromised WordPress uploads and disposable hosting, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious sites. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9927

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 http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a837cd71183---nalufapom.pdf
    • http://cnex.cc/images/blog//file/guwalepezubozowolavedox.pdf
    • https://skyzoan.com/cake/beta/userfiles/file/84265921738.pdf
    • http://susutour.com/userfile/file/24964446454.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16079ea6d9b712---78204239132.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/771adc6488cca1497ff8eba8e754d5bc/ziliguvinizoxuguba.pdf
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608cc4d186bfd---79677207938.pdf
    • http://finpacecuador.com/userfiles/file/fovokutusexafokaretex.pdf
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/578a63119014212d0d8c34866bf884e6/dekusorulifirup.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/jgkhn55mhfe7a7745ttqpj4oh0/35667172329.pdf
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086970e769ec---50211184270.pdf
    • http://vdadanang.vn/app/webroot/assets/files/jetotegile.pdf
    • http://accessprecision.com/userfiles/file/fepekifogokenutukowuviz.pdf
    • https://nikosdimos.gr/userfiles/file/28589226655.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1608117f607158---91123389477.pdf
    • http://mjsolankifoundation.com/fck/imagesfile/71860109511.pdf
    • http://stacjaregeneracja.pl/userfiles/file/50169083481.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1608a06b3a369b---fovepimaworanovuninosonek.pdf
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160a572418cf47---79961132113.pdf
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/e73a4635390b85cc3decb1073bafaa7f/pawejomezuvekozimotekipaj.pdf
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/m5k3bgpem2hbpfmsoj6a8k0oe3/mefujororojutajeb.pdf
    • http://www.advokat.com/app/webroot/img/fck/file/40623263583.pdf
    • http://greenlivinggarden.com/htdocs/UserFiles/file/25604557409.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=lucky+patcher+cit+game
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e19c.bin
f3e36a8e0f95d745d466bf420b067b71000629171489b530b392903a7349ae41
pdf-font-stream PDF embedded font (sfnt) at offset 0xE19C 10648 bytes
font_01_sfnt_off0000fa15.bin
12c731247e4bbf7a8045bc120b07944ea6fe78ee73afe53f487aa151fe87b8b2
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA15 28996 bytes
font_02_sfnt_off000132f1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x132F1 16792 bytes
font_03_sfnt_off00014b02.bin
7d15b2d6d265aaca51dda18faee70a1b8fa9d95ed54cb111fb0895789092f9ae
pdf-font-stream PDF embedded font (sfnt) at offset 0x14B02 16312 bytes