Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff9563ec1da3fb46…

MALICIOUS

PDF

70.2 KB Created: 2021-09-17 20:49:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c4dc42736bb6ee2d77f4ed3dd7f9ad22 SHA-1: 4d0c4c8d52f5219a03019acdbe792f9e103e90ec SHA-256: ff9563ec1da3fb463fcba8a7d1d525d493b5806ed3a5d4fc4d31895437a87221
176 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics point to the PDF being a link farm, with many URLs hosted on potentially compromised or disposable domains. The presence of external URIs and link farm characteristics suggests the document is designed to redirect users to malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://medvor.ru/uplcv?utm_term=sleep+as+android+review PDF link annotation
    • http://vtaky.sk/media/file/84882335537.pdfIn PDF document text
    • http://tmacfashion.com/ckfinder/userfiles/files/76048961345.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/99498206869.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139ffa59e659---23453885325.pdfIn PDF document text
    • http://mcenterdk.ru/fck_editor_files/files/96342697744.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a5bbf16a3---diposopobumamifunexuzer.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/79991755921.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613f30eb5553a---ladizofilisagisejebaw.pdfIn PDF document text
    • https://b7b.reviewz.eu/app/webroot/files/userfiles/files/kebemoronurigafaxulafegi.pdfIn PDF document text
    • http://sgd42.ru/userfiles/file/77285524497.pdfIn PDF document text
    • https://proektasis.gr/admin/spaw2/uploads/files/balufutojarukarafi.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/62496068628.pdfIn PDF document text
    • https://areicon.com/images/file/raweruxawe.pdfIn PDF document text
    • http://12shio5.com/contents/files/26763497675.pdfIn PDF document text
    • http://crescentcarpets.com/userfiles/file/9191596107.pdfIn PDF document text
    • http://greathorserider.com/ckfinder/userfiles/files/nomamijotusivatutejole.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1614067de6b194---sawaremigalifinosuj.pdfIn PDF document text
    • https://jjcfurnituremaker.com/userfiles/files/1987590344.pdfIn PDF document text
    • http://swvocal.com/data/se2/file/2913467553.pdfIn PDF document text
    • https://irastuff.com/admin/ckfinder/uploads/files/xibimabulim.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/fisegepipuw.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16132e999740b8---modidode.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_off0000b35f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB35F 10512 bytes
SHA-256: 12023f96def811d2da66c4297a844f6a9ee1d967812410e5ca8023c48b2edc4f
font_01_sfnt_off0000cb5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB5F 15900 bytes
SHA-256: d22ba903a4460813996d062602f6dec97deaa05a03a7ec064f1ddbca5e7e7716
font_02_sfnt_off0000f3e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1