Malicious PDF — malware analysis report

Static analysis result for SHA-256 20ff3e8c87efa7c6…

MALICIOUS

PDF

68.8 KB Created: 2021-09-25 19:35:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a99326427ac3507a51b8950e43ae591e SHA-1: c4b9186258c6735af757c98ee11ec4dcf0093d49 SHA-256: 20ff3e8c87efa7c6a125503fe217532ecff248916ede189b8c14b86b934cfd43
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Numerous embedded URLs point to various domains, many of which appear to be compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://chcial.ru/uplcv?utm_term=chrome+web+store+for+android+download PDF link annotation
    • http://thesciencenetwork.org/uploads/files/53434918278.pdfIn PDF document text
    • http://restaurant-lyons.fr/userfiles/file/26590436606.pdfIn PDF document text
    • https://9ja-bet.com/userfiles/file/kegozuxufosi.pdfIn PDF document text
    • http://ilovechardonnayhills.com/userimages/31104314298.pdfIn PDF document text
    • http://razzledazzleevents.in/userfiles/file/jegep.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109062119263117.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/pijarigulokemuvirevukeju.pdfIn PDF document text
    • http://inbeeldt.nl/userfiles/file/vamobak.pdfIn PDF document text
    • http://bidadapatidar.com/userfiles/file/86027424764.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613358536d26b---vanibilu.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/8ski97hqsuvhoh08dgmpl6tfcr/58075899912.pdfIn PDF document text
    • https://nocnepal.org.np/ckfinder/userfiles/files/delidozufow.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/161442c82e7433---xizelorafapi.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/98152438341.pdfIn PDF document text
    • http://tareeapartment.com/user_img/files/57011766427.pdfIn PDF document text
    • https://divetechmarine.com/contents/files/nesejirajixo.pdfIn PDF document text
    • http://aburobocon2019.mnb.mn/uploads/files/4795268712.pdfIn PDF document text
    • https://concurs-euclid.ro/upload/fck/35403053189.pdfIn PDF document text
    • http://digilit.ir/basefile/digilitir/files/wolep.pdfIn PDF document text
    • http://www.ekoforte.com/upload/file/82011465926.pdfIn PDF document text
    • http://uniquecharacters.com/upload/files/jajidepagos.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/98d934d9fb7e2f0db94edaca4d3f76f5/mixizomi.pdfIn PDF document text
    • http://spartaksedlec.cz/spartaksedlec/userfiles/file/26768234698.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_off0000ad99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD99 15280 bytes
SHA-256: 396fb55819df069d8613562b629ed34557063025c543992fa771a261ef70bb2b
font_01_sfnt_off0000d498.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD498 10876 bytes
SHA-256: b1cc6f4ebcde2a66f486579b5e38b3d93afea661c6e1998be03d2626a215ff69
font_02_sfnt_off0000ed9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1