Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cb79ebc7c68a95b…

MALICIOUS

PDF

80.2 KB Created: 2021-09-17 16:45:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 140318348a0be3b56958231a9cc9365b SHA-1: 510c6aca448fb0e732a9ab0ee0d4db13f22cf08c SHA-256: 8cb79ebc7c68a95b953e6075b23c6dabe8acb3c311d53ef62a6ebd71e00a2cf1
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which are identified as link farms on compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • 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 https://infrive.ru/uplcv?utm_term=serway+jewett+physics+for+scientists+and+engineers+6th+edition PDF link annotation
    • https://foodsafebox.com/ckfinder/userfiles/files/67947037192.pdfIn PDF document text
    • https://stomatoloska-ordinacija-rijeka.com/files/2947232733.pdfIn PDF document text
    • http://tjchenxing.com/filespath/files/20210904120658.pdfIn PDF document text
    • http://aguito.madteam.net/ckfinder/userfiles/files/dinobifip.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139da8a6308c---pimufinenap.pdfIn PDF document text
    • http://vinhosnorte.com/images/files/nirozeda.pdfIn PDF document text
    • http://moskvaznaet.ru/upload/files/jemamepi.pdfIn PDF document text
    • http://aquitaine.annuaire-regional.com/ckfinder/userfiles/files/sosoditolasituzil.pdfIn PDF document text
    • https://limsurdua.com/contents/files/gikezutelapidubego.pdfIn PDF document text
    • http://geoass.eu/userfiles/files/40417596331.pdfIn PDF document text
    • http://tokstar.com/_UploadFile/Images/file/bogolikekutan.pdfIn PDF document text
    • https://protum.se/file/12312951427.pdfIn PDF document text
    • http://devison-matras.ru/upload/file/42346008020.pdfIn PDF document text
    • http://majortaylorride.info/images/uploaded/file/46129257041.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/161420e7f4b0cb---robeburozores.pdfIn PDF document text
    • http://elencostruzioni.it/userfiles/files/88485797298.pdfIn PDF document text
    • http://serbanindustrialconstruct.ro/uploads/files/geguva.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/16141159816799---vuwimobok.pdfIn PDF document text
    • http://thenext.pk/userfiles/files/33878970.pdfIn PDF document text
    • https://thietbigas.net/media/files/pavofizazezaxa.pdfIn PDF document text
    • http://chandigarhdatarecovery.com/files/file/vajixisugiferefepedus.pdfIn PDF document text
    • https://aiwcecckolkata.org/FCKeditor/file/20803953994.pdfIn PDF document text
    • https://hattshopping.com/admin/assets/images/ckfiles/kawuzuw.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_off0000cff2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFF2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e809.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE809 11424 bytes
SHA-256: 57932204fe65f27b04c9b6c0b4923dad0812208727068cec46aa39d9c86dc1f7
font_02_sfnt_off000102c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C8 18624 bytes
SHA-256: 9a38b4f4571e4d8d58a40c2e19510e0b1c83a1b35b92185562af6cbfe721f3bc