Malicious PDF — malware analysis report

Static analysis result for SHA-256 915ecbbb44caff8b…

MALICIOUS

PDF

78.1 KB Created: 2021-09-19 11:06:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: ef5825fda6eb467227b2bd0b12ab1a3d SHA-1: 9f26a45fa7a3c784a8c357eef0569c6a971b2931 SHA-256: 915ecbbb44caff8bce2e4d1d5dd4a1c240697fd7c7230672686aab824de5f806
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, suggesting it attempts to redirect users to potentially harmful websites. The presence of a link farm on disposable hosting further supports a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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
  • 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://krisoc.ru/uplcv?utm_term=how+to+delete+all+messages+in+android PDF link annotation
    • http://bargiel.com.pl/ckfinder/userfiles/files/vezokekuw.pdfIn PDF document text
    • https://thehouseproduction.net/file/nuripujuginajulolonaz.pdfIn PDF document text
    • http://showdoimovel.com/files/files/72421494497.pdfIn PDF document text
    • http://roocenter.ru/upload/file/dowukizubugimefos.pdfIn PDF document text
    • http://ambartakip.net/belgeler/file/sofapipupeseni.pdfIn PDF document text
    • https://www.adoz.cz/ckfinder/userfiles/files/64773882367.pdfIn PDF document text
    • https://www.tulsarad.com/my_content/js/ckfinder/userfiles/files/71227554142.pdfIn PDF document text
    • https://pankajplast.com/ckfinder/userfiles/files/bedadizirasafadejoloxagi.pdfIn PDF document text
    • http://crisismobile.com/ckfinder/userfiles/files/worepe.pdfIn PDF document text
    • http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/geleretoduzamolawupimoze.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/sovigorifokavinijubofoka.pdfIn PDF document text
    • https://shinko-tw.com/UserFiles/file/60514670172.pdfIn PDF document text
    • http://wonikquartz.com/upload/editor/file/1630960590.pdfIn PDF document text
    • https://unaizahic.com/Files/files/75432982566.pdfIn PDF document text
    • http://xn--d1achljw0b.xn--p1ai/content/upload/surofofunazowusaberame.pdfIn PDF document text
    • http://inkjetartandimage.com/Uploads/file/98625133408.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210911081106189.pdfIn PDF document text
    • https://www.douggoodkin.com/admin/ckfinder/userfiles/files/91105672748.pdfIn PDF document text
    • http://dorisemitchell.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/noparur.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16135f18f7df01---gozegezixu.pdfIn PDF document text
    • http://itemclinicchina.com/ckupload/files/78807593523.pdfIn PDF document text
    • https://securitydm.rs/slicice/file/45451360190.pdfIn PDF document text
    • http://mediasingrid.com/js/new/fckeditor/userfiles/file/zolegilulaluxifavupar.pdfIn PDF document text
    • http://alhambra.kopanramen.com/uploads/files/99939771996.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16142b403b7e8b---miboboxukevupikuzafaxeda.pdfIn PDF document text
    • 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_off0000ce65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE65 17068 bytes
SHA-256: 5c5fa8848639f3b6696b0405068e9dcd6f66a1b647a09c3c9ef1f7944b7b3410
font_01_sfnt_off0000fa3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA3C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011253.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11253 10668 bytes
SHA-256: 57a5295f6c6cc9473c7130ae5fa68075bf6aef8bab7f288577f6aedf8e777dfa