Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba4a2275b2d87e95…

MALICIOUS

PDF

88.8 KB Created: 2021-09-10 11:57:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b169e4f165587b7c686b1876eb751cf4 SHA-1: 8d2c2fe623ccf6116b8f90d34e2a237890d13978 SHA-256: ba4a2275b2d87e9577503386d50294610e645c2eb15d02e41847265314628476
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external PDFs hosted on various domains, many of which appear to be part of a link farm designed to obscure the ultimate destination. The presence of 'utm_term=wombo+premium+apk+download' in one URL suggests a lure for potentially unwanted software.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138cc9677d9d---zukakumesuxajubojugu.pdf In PDF document text
    • http://zhouzhuanx.com/v15/Upload/file/2021910131482876.pdfIn PDF document text
    • http://ksiclubcom.ksiclub.org/svnprojects/DHD/Source/images/files/gumoxagijuguzi.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/161394554a3b18---45417184785.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/54613994815.pdfIn PDF document text
    • https://tekartltd.com/upload/files/39483749426.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/buxaki.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/23781494033.pdfIn PDF document text
    • http://synerfreight.com/syner_upload/images/files/jidafalumazawugituzimofem.pdfIn PDF document text
    • http://thewellmanteam.com/userfiles/files/50814894016.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/43987252353.pdfIn PDF document text
    • https://sitycare.com/FCK-UserFiles/files/25025809100.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/jugogaguzitavare.pdfIn PDF document text
    • http://oshcongregation.com/userfiles/file/satosojopifafixopasuzeze.pdfIn PDF document text
    • http://imhyuk.com/imhyukeditor/userfile/file/35948717547.pdfIn PDF document text
    • https://nanyangtextile.com/userfiles/file/31345983009.pdfIn PDF document text
    • http://adimhukuk.com/resimler/files/zalifuzexep.pdfIn PDF document text
    • https://sarna-zapiekanki.pl/ckfinder/userfiles/files/86389039177.pdfIn PDF document text
    • http://resheto.ru/users_images/fck/file/lavelarikeluziwosovamexiv.pdfIn PDF document text
    • http://esrafisek.com/images_upload/files/diwosebuxixidavotomo.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/29048274851.pdfIn PDF document text
    • http://campbellelectronics.com/uploads/divevazonogigugaf.pdfIn PDF document text
    • http://lapawan15.com/shop/fck_file/file/76655325448.pdfIn PDF document text
    • http://sentezetutmerkezi.com/upload/ckfinder/files/66845591385.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=wombo+premium+apk+downloadPDF 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_off0000f176.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF176 10696 bytes
SHA-256: d7ce246ff1480e839196d1fda13842d423752374bccd57d0f611ceba48b33e6d
font_01_sfnt_off000109b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000121c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C6 20096 bytes
SHA-256: 425ab633da22a846aedc9522bb9eb7c15b0653cbf6640bd1645c636f7dcd6017