Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a9f7a51366944a5…

MALICIOUS

PDF

96.7 KB Created: 2021-06-30 19:30:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: ed1e9018125ac4d599fddfce17e893c0 SHA-1: 58942af3fd06627af98c219e828e044a668ade16 SHA-256: 8a9f7a51366944a55b443936e1b21a30affdaf47ad105aa332bdaaba3a22b35b
156 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal a link farm strategy, with numerous URLs pointing to compromised WordPress sites and disposable hosting, suggesting an attempt to distribute phishing content or malware. The embedded URLs and the nature of the heuristics strongly indicate a malicious link distribution pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://crysiq.ru/uplcv?utm_term=javascript+format+date+to+string PDF link annotation
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160874d189410f---sosenapufokufuv.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/f8477296050e52b46f2fdac485c567b2/15910266319.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9b3bb1133---sewixiguxar.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac0795127a2---bomafevisegobop.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/5302606933.pdfIn PDF document text
    • http://zgkimsteszew.pl/img/upload/files/kuvebezuremezajomigivoj.pdfIn PDF document text
    • http://eszixv.hu/ckfinder/userfiles/files/5391118375.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/7nuirn4vsp601jdq7v82jk7652/21532115658.pdfIn PDF document text
    • https://bcbc3399.com/upload/files/laxibabekupalanukasiwok.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/90757ba7cd9e241847bfe817182db47d/jakelevuxel.pdfIn PDF document text
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/heppa17htjgqqpl5f8lbibkakd/39002527709.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/38517352991.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1606f30b51667e---xezawifamefepojugakati.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/e16679255070ef53a473e92f535b13cf/4703144380.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/e394c78c03e34af57e8bba00b7837814/xasirinovib.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/7umcea2nrhagcavqst5271h8n0/jejazopuzomakiwuruzoda.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607be195bd66f---befokugilarajevuliza.pdfIn PDF document text
    • http://vankouwenenmastop.nl/UserFiles/file/wefusimirolijodowafebot.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607199bb93b51---lenaxibox.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607720eb80721---36864164332.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/berarawubin.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/5a187c9c6031ab2d28dd1b3a8510b556/gixitopog.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/bpvv9qktbk0u1ig7ui3tavlafd/xulabikida.pdfIn PDF document text
    • http://cathyknightwaite.com/ckfinder/userfiles/files/gigasuvip.pdfIn PDF document text
    • 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_off00011360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11360 18364 bytes
SHA-256: f8f422be5f62cf16cddad6aa932b64918f59f6f6901203afec5a55f30164c71c
font_01_sfnt_off00014438.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14438 10976 bytes
SHA-256: 18c0b6a092ecbf68bd8719b4ae98bee50a1e565a00f39eddeb02b024bf4a1674
font_02_sfnt_off00015d84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15D84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1