Malicious PDF — malware analysis report

Static analysis result for SHA-256 86633fb88c8e341f…

MALICIOUS

PDF

98.4 KB Created: 2021-09-17 18:50:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 230402c62cc4aa6a1f31aff67efae53a SHA-1: 5202af26a2dbb94ecaa541eb9f6d4345428b896f SHA-256: 86633fb88c8e341f52fda624139713eb631bcd6fd8a2a33ea5a98f54e502ec81
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a non-clustered link farm on disposable hosting. While no scripts were explicitly extracted, the nature of the embedded URLs and the heuristic firings suggest an attempt to manipulate search engine results or redirect users to potentially malicious content. The file's creation by wkhtmltopdf suggests it may have been generated programmatically.

Machine Learning

  • Nyx PDF Classifier clean score 0.0738

Heuristics 5

  • 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 http://reginahajo.hu/_user/file/piwajasifojobiduteg.pdf
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136ea1eea521---duzolakolepotiboluguka.pdf
    • http://ms-domino.eu/images/file/files/74695100716.pdf
    • http://fcgo.tw/uploadpic/files/89157762057.pdf
    • https://ahreco.com/uploads/news_file/kiwatafazuxibadov.pdf
    • https://dacola.com/upload/files/vopis.pdf
    • https://skywaynepal.com/userfiles/file/15352503016.pdf
    • http://leaguengn.com/userfiles/file///gimubemidanugazilu.pdf
    • https://igescanada.com/ckfinder/userfiles/files/54700161268.pdf
    • http://turnwealthy.com/ckfinder/userfiles/files/jukugiwupovekaramenimi.pdf
    • http://deltools.com/userfiles/file/99063733894.pdf
    • http://biancoacolori.it/userfiles/files/jesogukov.pdf
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131abdfb9ace---21456538447.pdf
    • https://habrit.tw/ckfinder/userfiles/files/vodojefobasopexufagebiza.pdf
    • http://resumesfromabove.com/userfiles/file/kakudugirupate.pdf
    • http://stroykap.com/application/views/stroykap/userfiles/file/56745162668.pdf
    • http://ominocoibaffi.it/userfiles/files/95027393355.pdf
    • http://aftckwt.com/uploads/file/10737061408.pdf
    • http://okun.su/upload/file/fanofire.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ebf002b265---119596801.pdf
    • https://hanomanberjaya.com/contents/files/64117793841.pdf
    • http://ghinelliarchitettura.it/userfiles/files/15416874600.pdf
    • http://honeystraw.com/uploadfiles/file/84365411394.pdf
    • https://dwitunggaljaya.com/sitefiles/file/mezusolovasaru.pdf
    • http://kesifveotesi.com/files/13276618280.pdf
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/96611671034.pdf
    • http://jeykrishnaclub.com/images/file/tinat.pdf
    • https://pensionradvanice.cz/res/file/ritodepexatirifivigodi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=kora+online+apk
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001274c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1		 pdf-font-stream PDF embedded font (sfnt) at offset 0x1274C 16792 bytes
font_01_sfnt_off00013f63.bin
e631909369e10e1892cd16dee28ff028fe2a3dfca52dfa310d72195a5fb49e87		 pdf-font-stream PDF embedded font (sfnt) at offset 0x13F63 10064 bytes
font_02_sfnt_off000155c5.bin
70d936e1839261564f49ecbd314ba261e58c5794368c25e41a01bf9f3e99c77e		 pdf-font-stream PDF embedded font (sfnt) at offset 0x155C5 19316 bytes

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