Malicious PDF — malware analysis report

Static analysis result for SHA-256 a76f8e323b06d130…

MALICIOUS

PDF

82.3 KB Created: 2021-09-02 17:12:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c318b895b84b3fca2635ea75b20d5662 SHA-1: af94df22a3b5830a26d33cdf1cb9a8e951696b8e SHA-256: a76f8e323b06d1301669f002d38e87034c550796fb516dd69c6baca17ad1913b
164 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple domains, some of which are hosted on compromised CMS uploads or disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of a 'download button' heuristic further supports the lure mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://falerisztika.hu/tmp/vajudibub.pdf In PDF document text
    • http://unipsyclinic.com/userfiles/file/20210720163658.pdfIn PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/kirilepuburugusizafubef.pdfIn PDF document text
    • http://dribblebar.pl/userfiles/file/82687912996.pdfIn PDF document text
    • https://nieruchomosciturystyczne.eu/files/file/jupuwutowozesaju.pdfIn PDF document text
    • https://pasifikendustriyel.com/userfiles/file/10057331663.pdfIn PDF document text
    • http://ping-property.com/user_img/files/zaladixevalesokopuzo.pdfIn PDF document text
    • http://stigstudiotecnico.it/userfiles/files/tofugututuxove.pdfIn PDF document text
    • https://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cd5456969a---tekamemesevulaxu.pdfIn PDF document text
    • http://abwingsbuffalo.com/uploads/files/37580505654.pdfIn PDF document text
    • http://chromavials.com/d/files/55713606576.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a91dc0c8f73---mozebizalorexoravamalova.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16088afcd4ec9e---8660293659.pdfIn PDF document text
    • https://envida-nieuws.nl/bsb_website/upload_fck/file/kaxujugirufudabumofusoj.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160f6069e7afc5---64654585837.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/cfbd649bb42a5fba29fb244ae5c34abb/72259749114.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba2148d277---3597245997.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607756b96803f---30681160.pdfIn PDF document text
    • https://xosobacninh.vn/webroot/img/files/foliran.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/89903646227.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612b073014b9d---kodoterewojonalazokaridu.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1609a017b8f7e1---dawubagijokibisiramimipe.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/fivude.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160934d81e8705---77954746584.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c44189343df---97379689511.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=subtraction+word+problems+year+2+worksheetsPDF 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_off0000d63e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD63E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE55 11504 bytes
SHA-256: 7403e82a2dcaba02cad610425e11011b5e6bd731960c352db6dfccd9060e04f6
font_02_sfnt_off00010945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10945 19676 bytes
SHA-256: 2ca278973a607fb16e5aefd6acc558982637cb0a465edadd55798ec1c42acd72