Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a8ecf9122c8acf…

MALICIOUS

PDF

84.3 KB Created: 2021-09-06 19:18:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 226452945b70bd485f40a4d8b24cdc5e SHA-1: e01caa9571842ebdd55bc0f5ec5998b5293b3bc3 SHA-256: 31a8ecf9122c8acfdebe70bcec702f79f8f226faf61695b6af96eb483ba62f27
156 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous links pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to redirect users. The presence of these links suggests the PDF is used as a lure, likely for phishing or to distribute further malware, aligning with the Spearphishing Attachment technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16097232a5163f---xapan.pdf In PDF document text
    • http://clingac.com/d/files/rizanuxizuxuzedilade.pdfIn PDF document text
    • http://archerelectricsupply.com/userfiles/file/xefojakamuzemeni.pdfIn PDF document text
    • http://deltools.com/userfiles/file/paxalamu.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/3c0501a6db16bb9ac9e4d094aa3c484d/tidurajuben.pdfIn PDF document text
    • https://feldmann.pl/userfiles/file/sizoxonotomofipop.pdfIn PDF document text
    • http://pi-consulting.ch/download/93007494137.pdfIn PDF document text
    • http://qzgyhs.com/Upload/file/69524424490.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/lhde324k2atmo2rpomhs38h2qj/povujufare.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/160869c3f09a4c---63966808736.pdfIn PDF document text
    • http://inventory-acepipe.com/images/uploads/files/92361155388.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/3f1e414e1951664e01b4b53271ccc1da/pafilepugejabudozajufux.pdfIn PDF document text
    • http://partnerplus30.ru/images/fornews/files/jojigiselelaloxekegekore.pdfIn PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/1b915e1681b740c080e087412b804ce5/77059276978.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca6810ff63---26018204990.pdfIn PDF document text
    • http://skomi.ru/img/files/file/99416086886.pdfIn PDF document text
    • http://gloria-eurex.com/images/blog//file/jovakegokiwosenigofabodew.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/kubine.pdfIn PDF document text
    • http://www.cerel.eu/images/wyswig_images/file/vinetaxitoxabagoputumopag.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160897e57772af---81864868550.pdfIn PDF document text
    • http://fedime.org/imagenes/darefuvupajeporoj.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/16076339ada481---60812762.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/furudotexudami.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/00acb697f9b432d9b10ec6b729197a26/69602996066.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160982e1d3c0e2---difoxakoxodureteju.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/160b826717164b---nemixupasujaviwovamejo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=terapi+morbus+hansen+pdfPDF 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_off0000e144.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE144 18900 bytes
SHA-256: 9c1f319df6effa520efc3aa6dbf39f72ab0a8272ecb0cd528dcaea5ee6ab5141
font_01_sfnt_off000112c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112C7 10820 bytes
SHA-256: 8eec10609d870766c39764aa0fbd63cd89fc998d11a7c1472c591b4d7bad86d1
font_02_sfnt_off00012b3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1