Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a26348dd95fb14e…

MALICIOUS

PDF

70.6 KB Created: 2021-09-19 23:25:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 71cfe56775496ffd4cbddc9b568e8b79 SHA-1: 23020aeeeddd2af18ee88d3345de6a3fb651da10 SHA-256: 5a26348dd95fb14e2504d35b0bc9c06aba55298e9c74e71f250eee57e3fb556f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URIs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or malware distribution lure. The PDF structure and embedded URLs point towards an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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.
  • 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://hiroyoung.com/data/files/korirexim.pdf
    • https://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/43827831533.pdf
    • http://taiwanquinoafamily.com/shopadmin/upload/files/rozojod.pdf
    • http://cathugo-catamarans.de/res/wysiwyg/file/5541283769.pdf
    • http://jocoseatee.com/userfiles/files/nuvoma.pdf
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/1613310a291a8a---figirasikizufevugimoda.pdf
    • http://zhengfutz.com/v15/Upload/file/20219151617261991.pdf
    • http://askort.pl/Upload/file/50441059988.pdf
    • http://saringkarnwood.com/UserFiles/file/4522449758.pdf
    • http://zgic.ru/!upload/files/guvesivupizosek.pdf
    • http://osmed.cz/app/webroot/files/files/35411548298.pdf
    • http://gorsilawfirm.com/userfiles/file/85512702681.pdf
    • http://hk-keber.de/images/file/3841854821.pdf
    • http://pc580.cn/upload_fck/file/2021-9-1/20210901110259432120.pdf
    • https://www.dogandemir.av.tr/paketler/ckfinder/dosyalar/files/lobiduwuxevumanomaxipa.pdf
    • http://studio70.eu/userfiles/files/36165183463.pdf
    • http://www.corazondelsol.es/ckfinder/userfiles/files/56768885078.pdf
    • http://hoadon-dientu.net/images/files/4714959135.pdf
    • http://violetstudio.in/userfiles/file/pimasiloj.pdf
    • https://grupa-energia.pl/attachments/file/modepurasaf.pdf
    • http://2ds-creations.fr/userfiles/file/94495201198.pdf
    • https://creteservices.com/FCKeditor/userimages/file/raxer.pdf
    • http://cimkezes.hu/uploads/ckfinder/userfiles/files/pupobuzuvuzafi.pdf
    • http://ecovn.vn/uploads/news_file/kufegolo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=mod+apk+8+ball+pool+unlimited+money
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • 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_off0000b393.bin
0aa42a20bd26639b12b6ac4376459cf5306ab23d3b119548200e2cce740b5d4d
pdf-font-stream PDF embedded font (sfnt) at offset 0xB393 10932 bytes
font_01_sfnt_off0000ccac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCAC 16792 bytes
font_02_sfnt_off0000e4be.bin
3b676fc5109b272b87f840af8cd11ebe3b580fb4f4883191a418deb8b12a1dd6
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4BE 15752 bytes