Malicious PDF — malware analysis report

Static analysis result for SHA-256 87791ba8434954a6…

MALICIOUS

PDF

86.2 KB Created: 2021-09-08 21:58:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ee732ec82186aa6ebdd38d45be4d2ad3 SHA-1: f258e7900a5645806ffa3f8bcbae21cb99508dd6 SHA-256: 87791ba8434954a683f17eaa4dba6401918d2b9aaa3fbb07ffb74920587f80f5
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised or disposable domains, indicating a link farm designed to lead users to malicious content or phishing sites. The ML classifier and ClamAV detection strongly suggest malicious intent, consistent with a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • 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.
  • 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://queure.ru/uplcv?utm_term=starting+a+sentence+with+then PDF link annotation
    • http://na3.it/misc/file/tazedizofitotam.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/748d50b5d23591aefb28aea535f1e7c6/niwezip.pdfIn PDF document text
    • http://akpanlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/76787052099.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137ade0405fb---97060541051.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138006c78a99---76865949331.pdfIn PDF document text
    • http://ulleungroadtour.com/FileData/ckfinder/files/20210907_B0B2E858DC64AA67.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613693d5450a0---89832010686.pdfIn PDF document text
    • http://thebillionbottom.com/business_school/uploads/file/vomepeberukidu.pdfIn PDF document text
    • http://bekescsaba.varosom.hu/userfiles/files/jafujijimabutabaro.pdfIn PDF document text
    • http://escritacontabilidade.net/fotos/news/file/4151803591.pdfIn PDF document text
    • https://footballsod.com/images/ck-uploads/files/gudezobijelidudewegaramip.pdfIn PDF document text
    • http://scoutpate.com/userfiles/file/47099760018.pdfIn PDF document text
    • http://vipdiler.ru/files/file/gejiritelasumuse.pdfIn PDF document text
    • http://pnlestari.com/visitbali/image/files/579594923.pdfIn PDF document text
    • http://getdol.com/page_data/file/48622827141.pdfIn PDF document text
    • http://viprealestatebrokers.com/userfiles/files/musodasirojaxiweginufe.pdfIn PDF document text
    • https://robustbrakes.com/administrator/imagetemp/file/3937316027.pdfIn PDF document text
    • http://dlshixiang.com.cn/ckfinder/userfiles/files/vipumixigivalosage.pdfIn PDF document text
    • http://www.cpiequipos.com/assets/images/user_files/files/33130591607.pdfIn PDF document text
    • http://thebrownbag.vn/upload/files/gupuzefesevimufexupofiku.pdfIn PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/wujadaxi.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///zowudosilogi.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/33721214261.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_off0000e609.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE609 10504 bytes
SHA-256: dc68af261d6029b76eb0779c103144898a671cb1e6b2b641dc9a65fc5d6bb69a
font_01_sfnt_off0000fde4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDE4 20400 bytes
SHA-256: 1b3d6a42cb891ac0cb35d48cad6eafb431f84b3188417c586cc865d8032effea
font_02_sfnt_off000132db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1