Malicious PDF — malware analysis report

Static analysis result for SHA-256 88e155feec1fdce1…

MALICIOUS

PDF

77.7 KB Created: 2021-09-04 20:54:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 20c9201c52d8e3c50fcf0c64068ca683 SHA-1: 217304403d5759a180fb81e23009512d297cda4d SHA-256: 88e155feec1fdce18260cfcfcf0110b0ed7a68e6dab744acb7b2d9c5c7b22d18
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The document body is heavily obfuscated and unreadable, preventing a more detailed analysis of its specific content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/3d21034ff957fa1e40faa75df2ab2f24/ruxuzujab.pdf In PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bddc07bcfb2---20983033695.pdfIn PDF document text
    • http://stylowa-pss.pl/userfiles/file/63683448334.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160c3d6c50e9e9---68241743723.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160862454eb01b---58817151718.pdfIn PDF document text
    • http://stamforgtechnologies.com/uploads/nekewasim.pdfIn PDF document text
    • http://cuanhuaabshanquoc.vn/files/52877066529.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/8m6pe6k3m401tcrq5kk8612931/61930742013.pdfIn PDF document text
    • http://thankschicken.com/uploads/files/fokulit.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608442ee06e3c---62617322627.pdfIn PDF document text
    • https://airbays.com/userfiles/file/fovom.pdfIn PDF document text
    • https://dichocungtoi.com/userfiles/file/lopik.pdfIn PDF document text
    • https://egokituz.eus/files/galeria/files/kanavejudepimerugepo.pdfIn PDF document text
    • http://bigxra.com/uploadfile/file/2021072614200273499.pdfIn PDF document text
    • https://semut73.com/contents//files/sefab.pdfIn PDF document text
    • http://dvarenda.ru/upload/file/lexerixakewo.pdfIn PDF document text
    • https://srmhospitalities.com/images/bulk_images/files/3496437672.pdfIn PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612c768735512---bolisopuverivopubev.pdfIn PDF document text
    • http://hnkingdee.cn/Files/file/20218513611.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/3bf776748f1a89f01c5a598ce875bc58/32195195609.pdfIn PDF document text
    • http://red-persimmons.com/upfiles/editor/files/67695638069.pdfIn PDF document text
    • http://klimatyzacjaradom.pl/userfiles/file/88965602698.pdfIn PDF document text
    • http://iglozawiercie.pl/zdjecia/file/sikumutiwezexebapetij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=programa+foxit+pdf+editor+gratis+en+espa%C3%B1olPDF 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_off0000c597.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC597 18412 bytes
SHA-256: 9af27a5632953bdcabb4c9f81ec73608693f9d11c907e34caa7b3a557dbef630
font_01_sfnt_off0000f557.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF557 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010d6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D6E 11148 bytes
SHA-256: 2935dab43d79312ed58115a31463d00b7c1ad8cafbd30366b6abbf475be014fe