Malicious PDF — malware analysis report

Static analysis result for SHA-256 a557b7cb12e4748c…

MALICIOUS

PDF

86.3 KB Created: 2021-09-16 21:04:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 550e0409826b55fae02cd7d6acc339e5 SHA-1: 8a62ca602af981e5b39f15a17fbf0c091ca2e438 SHA-256: a557b7cb12e4748c3e6ce329e4c372eb3cd2710afbb877a903e2bf72cb7ecc8d
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as containing a link farm and pointing to compromised CMS uploads, indicating a phishing or SEO poisoning attempt. The ML classifier and ClamAV detection further support its malicious nature. The embedded URLs suggest the document's purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5261

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://wastran.ru/uplcv?utm_term=best+emulator+for+windows+7+32+bit+2gb+ram PDF link annotation
    • https://lifo-sea.com/ckfinder/userfiles/files/pagenekiwi.pdfIn PDF document text
    • http://goldenstarhotel.vn/images/uploads/files/dafepugekiwow.pdfIn PDF document text
    • http://wxeina.com/userfiles/files/1004472775.pdfIn PDF document text
    • https://perfecthospital.net/ckfinder/userfiles/files/ponid.pdfIn PDF document text
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/rariwi.pdfIn PDF document text
    • http://ustunongel.com/image/files/21464134532.pdfIn PDF document text
    • http://master-br.ru/img/file/winupajagojeg.pdfIn PDF document text
    • https://12tiga.com/contents/files/nasatureton.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/feturomijawusakaboda.pdfIn PDF document text
    • http://chretkinia.pl/userfiles/file/91169686603.pdfIn PDF document text
    • https://francoisdaulte.com/ckfinder/userfiles/files/7111050989.pdfIn PDF document text
    • http://rheumatology.institute/upload/content/file/ruvumesab.pdfIn PDF document text
    • https://www.habitat-morvan.fr/ckfinder/userfiles/files/26102657799.pdfIn PDF document text
    • http://ilink.pl/userfiles/file/vuzudid.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613422fe5ada2---42274873733.pdfIn PDF document text
    • http://squash-fitness.cz/userfiles/file/lamaledimuzebijakexa.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614341a27b29d---12786457862.pdfIn PDF document text
    • http://lakshimi-kaatsu.com/user_data/packages/default/imgfiles/nofaredarumadag.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/sasabuxuxepolutu.pdfIn PDF document text
    • http://rsport.eu/yonexshop/static/file/69791645818.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1851ed0ec23daebef3f200a0fc58405a/70654299801.pdfIn PDF document text
    • http://aranysolyomfeszke.hu/editor_up/11972860097.pdfIn PDF document text
    • http://nuitsdartistes.eu/images/file/tebojel.pdfIn 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_off0000f313.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF313 17932 bytes
SHA-256: 475c76ac7791e63aad104f2d3712c1d3cef59fa60fb9340a21095caa15dc2fc2
font_01_sfnt_off0001221f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1221F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013a36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A36 11420 bytes
SHA-256: 9bfac337eb90564dbf50ddc1701c7d8cbdcc9a2cd740df5eebc25278c6c0f632