Malicious PDF — malware analysis report

Static analysis result for SHA-256 ed18e50123110e97…

MALICIOUS

PDF

84.3 KB Created: 2021-09-13 14:50:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: a8e53e52f4f5d373fb0dda887a35fa78 SHA-1: cb562d2dd16470291b07fd1fdf5d0bc5f23b5294 SHA-256: ed18e50123110e972f1a3e54e2afb502678cedbd3dc523ce92fcb19ff0e32420
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Analysis reveals it functions as a link farm, with numerous embedded URLs pointing to compromised or disposable hosting domains. These links likely serve to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://krr-nfe.com/suratnfe/UserFiles/File/tedivobivivizixaj.pdf In PDF document text
    • https://chsins.tw/uploads/files/202109131421329142.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/hiqu0f3urdatflerbg5v8so0s3/sepofipirotipeme.pdfIn PDF document text
    • https://qwert5.com/psum/admin/userfiles/file/55812421117.pdfIn PDF document text
    • https://etevent.itweald.com/uploads/files/61314a89935ca.pdfIn PDF document text
    • https://kibledergisi.net/resimler/files/gewotanozajiwazedu.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4dd89dd21---16413392765.pdfIn PDF document text
    • http://honmamon-s.com/img_seminar/userfiles/file/luganotewuvejovevidowipag.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/161384eebc5f94---lexakosalefusa.pdfIn PDF document text
    • http://adwokaci-pila.pl/userfiles/file/4852188433.pdfIn PDF document text
    • http://farmaciafoglia.eu/userfiles/files/62307705204.pdfIn PDF document text
    • http://belgium-ex.com/images/blog/file/46936614251.pdfIn PDF document text
    • http://runnersavezzano.it/public/userfiles/file/luxigotowetezubamoxa.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/82800892639.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/16221558300.pdfIn PDF document text
    • http://marchmont.ru/imgs/file/4689419165.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/48954233183.pdfIn PDF document text
    • http://htwy.com/upload/file/49072023441.pdfIn PDF document text
    • https://skywaynepal.com/userfiles/file/pasovukabufodunubumiditul.pdfIn PDF document text
    • http://isotech.si/uporabnik/file/64819106559.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/funifejutironazoloriwejuw.pdfIn PDF document text
    • https://nordavril.com/userfiles/file/xurinemuxodofatofabafow.pdfIn PDF document text
    • http://copy-office.it/userfiles/file/50312573124.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=how+to+add+icon+in+android+studioPDF 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_off0000e24e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE24E 19184 bytes
SHA-256: 68ef41bc3e221ab161309b7d3832245bda058c82c1866164d865daa8ab2dc509
font_01_sfnt_off000113ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113CE 10364 bytes
SHA-256: 7df52a2a796b4c34072bf7ad924265454c7d6ace61311fba16a473adb881ae68
font_02_sfnt_off00012b5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1