Malicious PDF — malware analysis report

Static analysis result for SHA-256 55515b4457f654e2…

MALICIOUS

PDF

86.5 KB Created: 2021-08-09 03:55:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 01af711eacc187f16b4e46f0d10488f7 SHA-1: a5ae21ac5f6ce72c563c7501d3d245dfad288a96 SHA-256: 55515b4457f654e2295f6f0bc739c2c600412f55769ddba9ea9c6ec6e28ecd78
212 Risk Score

Malware Insights

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

The sample is a malicious PDF detected by ClamAV as Pdf.Phishing.Trojan. It contains numerous links to external URLs, many hosted on compromised WordPress sites, suggesting it is designed to redirect users to download malicious content. The presence of heuristics like 'SE_INVOICE_LURE' and 'SE_DOWNLOAD_BUTTON' indicates a social engineering attempt to trick users into clicking these links, likely to download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 9

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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=fallen+%282016+film%29+full+movie+online+free PDF link annotation
    • http://wsm.hk/images/uploadfiles/file/sulexaxotopiwumikim.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/i0jhdqlgu2khatalf8fijuirv7/23116041181.pdfIn PDF document text
    • http://rideabikenews.com/user_img/files/63580932226.pdfIn PDF document text
    • https://cowichanseniors.ca/userfiles/file/59702937525.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/udfodo3cvl5d9hg1up519c8ke3/60308117031.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/29ff12da31eda267ed66c6015e636629/bulixowob.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082b46405b54---jetifonupuzijaz.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/kaxadu.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbe8a55b6e---vemuvewarevadimafib.pdfIn PDF document text
    • https://magerp.org/upload/files/86188162552.pdfIn PDF document text
    • https://monyetmesum.com/contents//files/33290529205.pdfIn PDF document text
    • http://qytbearing.com/upfile/file/21059768532.pdfIn PDF document text
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/n3areger1l02ljhh3sph3gve7m/24246172757.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609c2af9681d4---79081219893.pdfIn PDF document text
    • https://mamap.in/ci/userfiles/files/30784324561.pdfIn PDF document text
    • https://pointvirgule.ca/upload/editor/file/lupan.pdfIn PDF document text
    • http://faceconnects.com/ci/userfiles/files/xeronovufizavixate.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1609af8d337720---fosizezuribejero.pdfIn PDF document text
    • http://zap-interactive.com/uploads/files/gigetivujudogafuvufavi.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8da2be097---fusikobuvofiriwunoperi.pdfIn PDF document text
    • https://higher-reason.com/wp-content/plugins/super-forms/uploads/php/files/5l2rs9s4j8dpifjst3jg9sh5bm/terokepazaremoxenib.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/4u9s8ppnheare1p4rbefugu9fv/1396744021.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16082c932e2c24---migolixiworemirosipiv.pdfIn PDF document text
    • http://zonweringbelgie.com/ckfinder/userfiles/files/rokosegelavexedinuzodiz.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/42p55u7qu322qi1jflnv2lu8fk/vijugekako.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_off0000ea7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA7E 17320 bytes
SHA-256: 5e30ac4250a9839de9e900e4ba1f7ef25524228c9d7945903666deb1b3eab192
font_01_sfnt_off00011812.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11812 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013029.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13029 10872 bytes
SHA-256: 54e84ac74da83b924dedc509ea4a1fb39ca29ec261d1bba794ed4fb14adddee7