Malicious PDF — malware analysis report

Static analysis result for SHA-256 223f23b7f88034aa…

MALICIOUS

PDF

74.8 KB Created: 2021-09-05 05:44:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 8cd7d9fde7ffb2ae1d561521760beee5 SHA-1: 2cff8dfb3313bc4825e1342104bd633bf3e83c13 SHA-256: 223f23b7f88034aab9857ce47c6d9795532c1fef28a21fa03b35e395061886c9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6960

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/6bf29d4a3de6a0d6d75a1858995455db/89567282380.pdf In PDF document text
    • http://an-ocn.ru/ckfinder/userfiles/files/zoduwesevavutubokemex.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b91054ccf2---timulazi.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/7989bf5ee4c605a8bdab997d33ca14d0/rowajipudisax.pdfIn PDF document text
    • http://palirna-frydek.cz/uploaded/file/41656829650.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/kn8833buhmphfu3udhuhbu859c/pebadexagu.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160ceb49c4b040---38554416095.pdfIn PDF document text
    • http://synerfreight.com/syner_upload/images/files/80297222888.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/30418695190.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/e806b298d6100196c3dc994d8830a4db/33193681436.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d9e29473d5c---17729214628.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/givajemozibejojo.pdfIn PDF document text
    • https://comfort8889.com/upload/files/kerumolugiwatebez.pdfIn PDF document text
    • https://svarovanijelinek.cz/ckfinder/userfiles/files/godakujumiguxu.pdfIn PDF document text
    • https://solidpractise.com/files/userfiles/file/59018754301.pdfIn PDF document text
    • https://cafesca.mx/ckfinder/userfiles/files/jetirilad.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/mazefuwinuvewuv.pdfIn PDF document text
    • http://khiensa.com/UserFiles/File/71184595940.pdfIn PDF document text
    • http://sincaremedicaltour.com/js/upload/91866548849.pdfIn PDF document text
    • http://denprokhorov.ru/images/file/57510568320.pdfIn PDF document text
    • http://sushinamu.com/uploads/files/falekuxenevajojidejudona.pdfIn PDF document text
    • https://bgmediation-flm.com/userfiles/file/7941865877.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=don%27t+stop+believin+ukulele+pdfPDF link annotation
    • 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_off0000cb5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB5C 18288 bytes
SHA-256: ea1ba4a4d038961d7f4fb71e095267bbe7ab5c23f7424003d4cbbac17a6c5f2b
font_01_sfnt_off0000fb32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB32 10664 bytes
SHA-256: 852b95df5eaf50b5711cfd29406a1b22e10ea2a2eb0ec18b888c94d0e940bcab
font_02_sfnt_off00011396.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11396 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1