Malicious PDF — malware analysis report

Static analysis result for SHA-256 82a0083c74dc57e7…

MALICIOUS

PDF

68.2 KB Created: 2021-06-01 00:10:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 9823a4d1b37cae05a93e44c8bf2d7efa SHA-1: 7a1c6f80e382ed556bf7f036a1186b8cbc1cfee9 SHA-256: 82a0083c74dc57e79c1c68b10ec0e47822d476e543cac95256e7897914fd5cac
156 Risk Score

Malware Insights

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

The PDF is detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous links to external PDFs hosted on compromised CMS upload storage and disposable hosting, suggesting a link farm designed to distribute malware. The document body, though heavily obfuscated, contains metadata related to PDF creation and a search term, reinforcing the lure of a free download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://celebicatering.com/upload/ckfinder/files/75590759691.pdf In PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/6eb926020237e07d8dd49ca8fabb3b25/5158211266.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084d07b89591---45165627119.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/f699dfcac1d9cd1c377a4f23fee1c710/dijemomibuworapadaled.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160800ad4efc63---96350721945.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/7rspanb1h15k690kliv26qtine/dadasivotexisuwozoxoz.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609684b885224---bimigugezaterijegitesepo.pdfIn PDF document text
    • http://1960vonsteuben.com/clients/d/df/dfb5e1b83ea85bfdc5ef1da934264264/File/44611560105.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a5815012472---52615627962.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b42f5e6ee9a---40924006132.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/84762873238.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2962b8488---zizewugegobevidoso.pdfIn PDF document text
    • http://www.dramayaramendes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607eee5b8771f---30353246740.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/14d773ec003a922d15d10016f527cb70/74325943083.pdfIn PDF document text
    • http://aldo-ins.com/userfiles/file/juzirifubasi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=introduction+to+geographic+information+systems+kang-tsung+chang+pdf+free+downloadPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC60 5796 bytes
SHA-256: dd8e83a75173cffcf92b73a6b22435fb5d3a3a7d2543fc96dc0b8c9e36792fa2
font_01_sfnt_off0000e014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE014 10348 bytes
SHA-256: f288c80d0374fd9664364e7edf6a61451a34c34874f34851ef68adfe0c4e5335