Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac18eb0c756188c0…

MALICIOUS

PDF

86.9 KB Created: 2021-09-04 09:45:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 15c6b3fc8b3967143185ecaddb1d0759 SHA-1: 68ddf74bade752f9a800112259749f047336225e SHA-256: ac18eb0c756188c0728b3b0ffc4547bcd852b9512fc2b58ea0fe9fcd468abf3f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. While no scripts were directly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://unipsyclinic.com/userfiles/file/20210615051947.pdf In PDF document text
    • http://akcjonariusz.com/UserFiles/file/pabunapuziwepitofubeko.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b913f3cece---wiboputegaf.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16076a60878f96---rakopubasotubu.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/65029014725.pdfIn PDF document text
    • http://cunningham-reunion.com/clients/7/73/7399477c88ef979e1ad3ac38e42cffcc/File/82978217617.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/a8cf510ff99e0b6601dc22c9f29ea9c9/kasekaroronevefazag.pdfIn PDF document text
    • https://healthcareadvisorsgroup.com/wp-content/plugins/super-forms/uploads/php/files/eeons0bhpass4n1cnvc3n6t8j6/70229418126.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/27b2ce18ba915e06bb4bf4be2c334cce/80933525703.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/f7lqhvh67sookt6fl42cspq8a8/jezepetaxemidi.pdfIn PDF document text
    • https://tiklatakip.com/calisma2/files/uploads/sijezozu.pdfIn PDF document text
    • https://baoyi-chuck.com/ckfinder/userfiles/files/tekiwurovub.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606cce246ce2c---82124402574.pdfIn PDF document text
    • http://pogservice.ru/userfiles/file/4365477293.pdfIn PDF document text
    • http://myxroad.net/upload/userfiles/file///kopikaguvet.pdfIn PDF document text
    • http://nipissing-lodge.com/clients/b/be/be32fa5c9d1e5a871f1efa0d35b29fe7/File/komuxajironubomi.pdfIn PDF document text
    • http://amdind.com/userfiles/file/zegasunilu.pdfIn PDF document text
    • http://krukaiart.com/userfiles/files/rugenosonijotixateje.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/d47u19orgcp2s6s3sk3dg2dkb0/nixoxigadivisejejugu.pdfIn PDF document text
    • http://igorodstore.ru/files/userfiles/files/26971471108.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/63196815663.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/wolemoziwiku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=types+of+interjection+with+examples+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_off0000e5c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C0 20452 bytes
SHA-256: 1e7ab050f375449bea1283bd168f66886021f1b0e593d93f260d875b0e5e5cc3
font_01_sfnt_off00011b44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001335b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1335B 11280 bytes
SHA-256: caa8e1d7f5c21e6fbeefd0dd33a9be2068faa9995218bb98f0f358317367dbf7