Malicious PDF — malware analysis report

Static analysis result for SHA-256 87bc0d8bff5a5955…

MALICIOUS

PDF

77.6 KB Created: 2021-09-05 02:30:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b7998c6c572c00c6e847bf3767c3e7eb SHA-1: 23cf931e0558d264a49267ab8ace84337e5c70e8 SHA-256: 87bc0d8bff5a595527281ac5febef3f0fbbf1c51091a96dc4c3fef60c4eb083f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links to external URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm for SEO manipulation or malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://harryreichert.de/uploaded_pics/News/file/ripavetajufopiwu.pdf In PDF document text
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/d8d8efdca1edb8fddf06d6b05d756a39/zosetuvuf.pdfIn PDF document text
    • http://summithigh75.com/clients/867147/File/71183984520.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210629_4E380E2F14FD323D.pdfIn PDF document text
    • https://masihpt1.com/contents//files/8132881016.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607faa24ba419---vegegojaxutamimamig.pdfIn PDF document text
    • https://doganagolosa.it/file/pubopazo.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7105950d5---5565236766.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b44193736ec---81494974232.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/1a8480d1721ff651d6b3a4951b8b248d/29023302085.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/fefalonalazopilige.pdfIn PDF document text
    • http://video-cycling.de/files/file/30474417034.pdfIn PDF document text
    • https://sealskinz.ru/files/file/39446649524.pdfIn PDF document text
    • http://lizhechem.com/upload/files/rugemazoxiduzisurip.pdfIn PDF document text
    • http://yossy.biz/userfiles/file/54162108966.pdfIn PDF document text
    • https://kolkatanagariksammelan.org/ckfinder/userfiles/files/40102124777.pdfIn PDF document text
    • http://nepodoshlo.kz/ckfinder/userfiles/files/fifozejiwabudonim.pdfIn PDF document text
    • http://avision-italia.com/userfiles/files/gixile.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/dogemufijelokaxawokikiza.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/a2922f561972b20ced6d9ba8f7a5ef73/banuzepivomukuwizojakeki.pdfIn PDF document text
    • http://msinternationalbeautypageant.com/clients/8/8c/8c0f0497d7166b07b5568c04be8084ca/File/71760817588.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/qvnnolq025id45a5skg69p19ov/9925294341.pdfIn PDF document text
    • http://wang023spa.com/userfiles/202107file/2021070912021570554.pdfIn PDF document text
    • https://www.axelendinggroup.com/wp-content/plugins/super-forms/uploads/php/files/6c9d0cddae953a2a96e9bec106ff2489/62720809656.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1608b3754cc2cf---getirezanazomufukukoxu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=competitive+exam+maths+books+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_off0000c958.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC958 10944 bytes
SHA-256: 07eab30943abc3b6effafe00d0cb8c416be6c1695a263eb0c0004bd192399397
font_01_sfnt_off0000e291.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE291 18060 bytes
SHA-256: 8fcf21f7c6f288e7fffd32c3c9d476b5d65e8ca27e6aaaa407a9e637ea267c05
font_02_sfnt_off00011071.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11071 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1