Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d6810e1b05f642…

MALICIOUS

PDF

73.9 KB Created: 2021-09-06 09:24:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 4f3913f9d2699311a7b318b201eec6fe SHA-1: 5b7f3b4e319a730743bcc41018e35b1d2e7820d2 SHA-256: 81d6810e1b05f64205b825b86d847b733319bbb18580c32948be25eaaa2d7cfd
162 Risk Score

Malware Insights

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

The sample contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users. It also features a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites, suggesting an attempt to distribute malicious content or phish users. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8530

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://sapaelitehotel.com/webroot/img/files/87260497920.pdf In PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1610c4d6f2e0f0---87553019735.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/16106af98a1058---90101790434.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/f6b3f1ceabc977849adf502a57b39996/37748505763.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1607e502fea69f---gewadopezakoratotiva.pdfIn PDF document text
    • http://saovietgroup.com/upload/FCK/file/59811520509.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160db5fb35a581---rejivitesupabunuvesive.pdfIn PDF document text
    • http://coss-wynn-reunion.com/clients/d/db/dbe3622004495b304d8703879a486b7d/File/7160406968.pdfIn PDF document text
    • https://mn-lawfirm.com/box/userfiles/file/kepasadived.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/1cc97d2dfd6e0a29c326f468713a2698/82248589524.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/16098920c50676---41131268717.pdfIn PDF document text
    • https://dolphinsolutions.net/ckfinder/userfiles/files/50492362511.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fc42e2dcd5e---53146953984.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae3590534b6---jopatesuwudere.pdfIn PDF document text
    • http://voxel-avocats.fr/uploads/file/tuxisagovuviv.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/44242394192.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/ff0e9dfd8fe7a512e189c3ac9a4cae5c/sidakowu.pdfIn PDF document text
    • http://portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/fagiwofafobumikoga.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/59346738072.pdfIn PDF document text
    • http://copy2d.com/ftp/image/file/dobixis.pdfIn PDF document text
    • https://ariaparvaz.com/basefile/ariaparvazcom/files/sovegomigapazaxu.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/160e75b3c0b264---tibibadalixupox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=alfa+romeo+giulia+quadrifoglio+manuale+o+automaticaPDF 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_off0000e97d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE97D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010194.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10194 10880 bytes
SHA-256: bc296409aba8c1dbe92f8a5b00ad9bcf7548a0ca43252af2b8b08c582d8a9c54