Malicious PDF — malware analysis report

Static analysis result for SHA-256 6994655f969aacf7…

MALICIOUS

PDF

132.8 KB Created: 2021-07-21 16:05:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8cdcc4fae3bde765ececb6a356987f72 SHA-1: 1518e4f9b26717f33ff7fbf82a1821dbb406fdf3 SHA-256: 6994655f969aacf748d2a1c2c9b70cc70c151233a885327cdfee8aae9a7d7dd5
124 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was detected by ClamAV as a phishing trojan. Static analysis revealed it functions as a link farm, directing users to multiple compromised WordPress upload directories and other disposable hosting sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather to host links.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.3062

Heuristics 5

  • 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
  • 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://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/62977848741.pdf In PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/afdf2e5ee3f7cbdc17f69c17ecf116c8/24340822209.pdfIn PDF document text
    • http://alemotta.com/resources/original/file/mukudekoxiwudojisivuzi.pdfIn PDF document text
    • http://mega.kz/media/upload/files/jitorat.pdfIn PDF document text
    • https://haysalon.com/public_html/userfiles/file/zurawonuvonofabep.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608888fb2d9f4---27430798311.pdfIn PDF document text
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/931b3bfee5062b7d6fd183b1f1ef640b/lafuduwago.pdfIn PDF document text
    • http://gpszone.hu/upload/userfiles/file/94172948492.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/69883605696.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bfafde82c1f---mamidejapigabokulapedana.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16070522a1fdc8---davejexanidunelaxikelar.pdfIn PDF document text
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/754da01b45398d50388c1fc4fbe0f8b2/95543171355.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/4571498523.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dc7c2b60d1---disekazox.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/e55c203eadd7dba185ecbdae44f843b3/dokupevizidakikokan.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160809ccf1e76a---bozoxenorodapesepala.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd8a11306d1---tiwupu.pdfIn PDF document text
    • http://www.startservis.sk/novy/ckfinder/userfiles/files/47150717756.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b8a67011dff---kaxiloxib.pdfIn PDF document text
    • https://feltshoe.com/userfiles/file/49820679558.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/c6r6rg10p43iusanoh0pagp19m/gawesirupasex.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b21d374ade8---jemulutere.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/omaspbaqtcct9hdp8bulat55t0/jowelomudiworibu.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/9a7ki3hu4n1eem7alk0295rhgr/15183612608.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c90c77a181a---jokoxerovatatalanotinube.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=structure+of+chromosome+pdfPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001c778.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C778 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001df8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DF8A 19504 bytes
SHA-256: 50520868223e1b9833c4bc9fb507aaa5a212d72e44e9f0f815c2ea62aa445cb0