Malicious PDF — malware analysis report

Static analysis result for SHA-256 b37f0d414cc763f9…

MALICIOUS

PDF

70.3 KB Created: 2021-09-26 17:27:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 35c44a0b4f0957dce78c71237eee97cc SHA-1: 232c54e3b3d8ef3ce072c759d40559bd4d7b2954 SHA-256: b37f0d414cc763f973ad64250b494fd17856a88f6990030c3c4ac391ab4ad959
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URIs, many of which point to external websites, suggesting a link farm or phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for a large number of links, further supporting the malicious intent. No scripts were extracted, but the PDF structure itself is used to host these malicious links.

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://smidgel.ru/uplcv?utm_term=how+to+screenshot+snapchat+ios PDF link annotation
    • https://alshamiltrading.com/alshamilfiles/file/8158811364.pdfIn PDF document text
    • https://www.artikel238.nl/emmwebbit/resources/ckfinder/userfiles/files/61837360741.pdfIn PDF document text
    • https://corpus.bg/files/fck/file/sebatizowaxurij.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/30844223211.pdfIn PDF document text
    • https://bloomland.com/sites/bloomland.com/files/69292915741.pdfIn PDF document text
    • https://khanoomhoteli.com/basefile/khanoomhotelicom/files/bevuw.pdfIn PDF document text
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/77851082489.pdfIn PDF document text
    • http://gemwishrs.com/ckfinder/stones/files/19394917086.pdfIn PDF document text
    • https://aksukartela.com/images_upload/files/25634581039.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/userfiles/file/fijadunok.pdfIn PDF document text
    • http://pushgroup.lv/userfiles/files/76718857733.pdfIn PDF document text
    • http://www.alliance-bio.com/user_data/editor/ckfinder/core/connector/php/upload/files/turuzalejebuzeb.pdfIn PDF document text
    • https://aodaixuan.vn/app/webroot/upload/image/files/51381471445.pdfIn PDF document text
    • http://drprdesaihospital.com/uploads/28205668730.pdfIn PDF document text
    • https://ripedzn.com/app/webroot/files/fckeditor/file/lokepeto.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/foxusozeline.pdfIn PDF document text
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b9fba1aa1f---jadevikerigediz.pdfPDF link annotation
    • http://konferencii.org/web/uploads/assets/file/59634415949.pdfIn PDF document text
    • http://lsbwg.com/ckfinder/userfiles/files/20210914/0312289504.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8e0b744e7---35409495531.pdfIn PDF document text
    • http://codemessaging.net/ckfinder/userfiles/files/judawimikizinadilebusa.pdfIn PDF document text
    • http://metamorfozyayincilik.com/userfiles/file/65952531456.pdfIn PDF document text
    • https://sapporomn.com/userfiles/files/7501444206.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/81e7f202fc80e1480ce2760e31a4363c/ragami.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_off0000b357.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB357 10500 bytes
SHA-256: b81291f29a52a54144ac9448b622eec9a7626592d6e59832e3fb9b0c3a797f88
font_01_sfnt_off0000cb38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e34a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE34A 15924 bytes
SHA-256: dc8f970e642c7c2bd7cd59c12feea01f0798c40d7efa754b99109b1755ec0e70