Malicious PDF — malware analysis report

Static analysis result for SHA-256 8df638e9cc0c5487…

MALICIOUS

PDF

80.7 KB Created: 2021-09-08 13:43:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 10e4958bb558362086d2c042beb006a1 SHA-1: a42305fd44e330161e45e85d6fe26ab14c34893e SHA-256: 8df638e9cc0c54870771dd7705d3ad4fd1228df7f06c2a9e8acb44ac7c8cec82
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised CMS uploads or disposable hosting. The presence of numerous external URIs suggests an attempt to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://chcial.ru/uplcv?utm_term=spring+worksheets+for+1st+grade+pdf PDF link annotation
    • http://avon-bratislava.com/files/files/9649602415.pdfIn PDF document text
    • http://borneneskontor-landsforening.dk/userfiles/file/renepeloxovapamud.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/kiwamoxolofomojisoper.pdfIn PDF document text
    • http://aunay-sous-auneau.fr/ckfinder/userfiles/files/29626574463.pdfIn PDF document text
    • http://mundialimportweb.com/userfiles/file/41362546543.pdfIn PDF document text
    • https://ww150002.linebot.net/upfile/files/20210907185135.pdfIn PDF document text
    • http://bordahusfeldolgozo.hu/editor_up/67923779510.pdfIn PDF document text
    • http://daiwavn.com/uploads/image/files/48587010634.pdfIn PDF document text
    • http://twozonechickenlasvegas.com/uploads/files/wofijolalapeje.pdfIn PDF document text
    • https://simpangkanan.com/contents/files/3222303531.pdfIn PDF document text
    • http://safetruck.gr/images/file/8449434125.pdfIn PDF document text
    • https://xn--22ck6bdp5cach0mc23a.com/ckfinder/userfiles/files/98265528837.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16134da6d9d85e---zedajurus.pdfIn PDF document text
    • http://around-sicily.net/userfiles/file/tabatirirorosujadapanojom.pdfIn PDF document text
    • https://tivicom.vn/upload/files/60077228309.pdfIn PDF document text
    • http://rileyillustration.com/images/agency/files/mapagexovasomiwuvorilu.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.com/filespath/files/20210905100551.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613062a635841---godiwukovamozon.pdfIn PDF document text
    • http://www.gobarging.com/uploads/textareas/file/53989912690.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/49020382170.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16131bab5b5154---suzibinomev.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613789b6b5e07---vozafegigibevito.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/koduxajafagoliboxigusuri.pdfIn PDF document text
    • https://envida-nieuws.nl/bsb_website/upload_fck/file/zajegogawunoro.pdfIn PDF document text
    • http://hightopeducation.com/cms_uploaded/file/kotopotatuxuwimugera.pdfIn PDF document text
    • http://mail-business.ru/uploads/file/66238482954.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_off0000d827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD827 16700 bytes
SHA-256: 6abfa20c6c4ba48466a375e7c4c073ac393db7d1468dd85654a975c3310ba697
font_01_sfnt_off00010395.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10395 11036 bytes
SHA-256: db52f84eddf349c2109fe4d163c8bbdc49009af42e93cd11d3048abf44510e98
font_02_sfnt_off00011d18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1