Malicious PDF — malware analysis report

Static analysis result for SHA-256 caefaca87b809982…

MALICIOUS

PDF

73.1 KB Created: 2021-09-19 06:13:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 4d8c3e79bfb1e41c42052871414a96a2 SHA-1: 5ac067141711e3d0332706f02b563f46fa65aad5 SHA-256: caefaca87b809982fffdc6697d5a66b4efc8e23d48c8b43b3ef83dd1b53f03d3
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 appear to be compromised or disposable hosting. Heuristics indicate this is a link farm designed to redirect users, with ML classification and ClamAV strongly flagging it as malicious phishing content. The primary function appears to be directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://synerhu.ru/uplcv?utm_term=afk+cats+apk PDF link annotation
    • http://akgwealthplanner.com/crm/files/5857224649.pdfIn PDF document text
    • http://naturalfurnish.com/userfiles/file/mesaxijumudekoxod.pdfIn PDF document text
    • https://sieuthigo.vn/upload/ck/files/59123035599.pdfIn PDF document text
    • https://matteagianotti.ch/userfiles/files/gaxowemobijipane.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132862aede95---gutubuvozuzawomubalef.pdfIn PDF document text
    • https://nedimgame.com/calisma2/files/uploads/modejibekidewopi.pdfIn PDF document text
    • https://coop-alternatives.fr/images/images/67317406677.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/d37de338add2e92e4aef653447a8e938/ganobosexeratexisitir.pdfIn PDF document text
    • https://adetexfoamgroup.centralcms.cloud/galeria/files/8453103211.pdfIn PDF document text
    • http://cleanyachts.it/writable/public/userfiles/file/pixopazekipu.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/aa03f5f3cd1c9d744dc934d262779df4/55082869101.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/nutuxegebowa.pdfIn PDF document text
    • https://indikino.com/ckfinder/userfiles/files/zufolijerojifur.pdfIn PDF document text
    • https://willes-gb.com/uploads/files/202109020410515223.pdfIn PDF document text
    • http://woykoff.hu/upload/file/32926493095.pdfIn PDF document text
    • https://mamap.in/ci/userfiles/files/45678891377.pdfIn PDF document text
    • http://bigbulkbags.ahmadpackages.com/survey/userfiles/files/73211332001.pdfIn PDF document text
    • http://surveycook.com/upload/tmp/202109/file/sabakusowinetugikuxode.pdfIn PDF document text
    • https://serka.com/serka/upload/files/zuserodovobop.pdfIn PDF document text
    • http://kirsanov-maslo.ru/uploads/30387041.pdfIn PDF document text
    • http://ngoinvest.com/uploads/ckfinder/files/ralapesevivor.pdfIn PDF document text
    • http://tythb.com/uploadfile/files/pobapesa.pdfIn PDF document text
    • http://vetsnab32.ru/userfiles/file/36798618446.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_off0000b8a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8A5 18460 bytes
SHA-256: 6b21e503d510ebfa8e9b7561255ef391fbd4516718ae97e24b8508c24d0c3783
font_01_sfnt_off0000e8a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100BD 9952 bytes
SHA-256: c1783e6d63cf9200f115e3f4f278d81c3c0cb0cbe17ac3f7f15462f6e2f99aa7