Malicious PDF — malware analysis report

Static analysis result for SHA-256 827a731d42c105a2…

MALICIOUS

PDF

88.5 KB Created: 2021-09-22 21:53:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 44b4e31bb515cc8a5ae76fbe50de56eb SHA-1: 9d9757eb3f0ddd6fe9be821d5381334e5a6c8b1f SHA-256: 827a731d42c105a2760bedcdb0f1d3eee73a1bfe621e29211eddbcffc92d4200
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads or disposable domains. The embedded URLs suggest an attempt to direct users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://ferrogep99.hu/static/media/file/wupomekokolezeponajakak.pdf
    • http://jd6618.com/jd6618/file/2021-9/file/LwpCms2021_09_11_14_43_39_9925.pdf
    • https://rrrc.us/userfiles/file/jerowegaderijifile.pdf
    • http://autothudo.vn/upload/fck/file/melabuxu.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16134f1c1752b8---barekaganejen.pdf
    • https://incoyun.com/calisma2/files/uploads/2117462140.pdf
    • http://mikailang.com/userfiles/file/20210912112154_531958629.pdf
    • http://budka39.ru/files/36595706054.pdf
    • http://coimbrasoftware.hu/images/uploads/files/17893957208.pdf
    • http://prinsart.ro/uploads/files/78105801072.pdf
    • http://tweedehandswikkelaar.nl/app/webroot/files/userfiles/files/mujuninupojadu.pdf
    • http://mjengo.org/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/31443615869.pdf
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/a5516be6225e8fde02d88899d2e15785/gabogagikabezewazepewi.pdf
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/161485f16b2f2f---43708318698.pdf
    • http://yushendesign.com/images_fck/file/1630736985.pdf
    • https://tavio.ru/files/file/71744259601.pdf
    • http://petgears.com/app/webroot/files/file/25912752945.pdf
    • https://mehreganimaging.ir/images/upload/files/devavepomuzesidonigax.pdf
    • https://volgogradexpo.ru/ckfinder/userfiles/files/72094522481.pdf
    • http://eapver.com/upload/ckimg/files/202109170015035054.pdf
    • http://sayarbobinaj.com/file/11915195446.pdf
    • https://zhbiotech.com/CKEdit/upload/files/5365172276.pdf
    • https://cissud.com/uploads/ck_editor/files/7305901875.pdf
    • http://sweatrinserepeat.com/ckfinder/userfiles/files/vekoremurakopideves.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=english+horror+movies+torrent+magnet
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2b8.bin
f9d208a8b8cb73f056a741f9161f5e8079ce6d4f027bab5e7b36288ec47f49e4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B8 19316 bytes
font_01_sfnt_off00012450.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12450 16792 bytes
font_02_sfnt_off00013c67.bin
bb6e2ea9f08f2eb53b6f42fe3e3642aea39abc088e9e3eee16f3c06b8144c3d3
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C67 10604 bytes