Malicious PDF — malware analysis report

Static analysis result for SHA-256 395a91a115b984e0…

MALICIOUS

PDF

82.1 KB Created: 2021-09-05 03:44:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: deaf476443d432287ba6f5ce93ede278 SHA-1: 36ca4c3d6fc1b1113a0cf6155ac1cc1c8aea6b22 SHA-256: 395a91a115b984e0d6d17bcd53cb668f75c1d285094d22f650ed629f1743f45a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many pointing to compromised CMS upload directories, suggesting it functions as a link farm for phishing or malware distribution. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the links and the detection results point towards a malicious document, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dd762506ae3---17213331937.pdf In PDF document text
    • https://cncunse.com/d/files/13653950183.pdfIn PDF document text
    • http://mytaylormadefamilyusa.com/clients/864113/File/2159868311.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c39c67d0e8f---menosutiwojojixuwipi.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/6613635995.pdfIn PDF document text
    • http://jia-longsofa.com/uploadpic/jialong151126/files/202108242245239535.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/viburobof.pdfIn PDF document text
    • http://thietbimaugiao.vn/Images_upload/files/79324711509.pdfIn PDF document text
    • http://portamarioarchitetto.eu/userfiles/files/samuruf.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16094aca90d269---56776591605.pdfIn PDF document text
    • http://101-games.ru/images/uploads/files/simoxebuvumiji.pdfIn PDF document text
    • https://wupaojichangjia.com/d/files/21471535091.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/megiwi.pdfIn PDF document text
    • http://thuduchouse.vn/pics/file/44943196831.pdfIn PDF document text
    • http://wu-pao.com/upfiles/editor/files/83041018877.pdfIn PDF document text
    • https://sensesgrouphk.com/louis/STARKGROUP/ckfinder/userfiles/files/jokapemefemaju.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/238803920975fa102fc73ded4e6598c2/bogagajepaxozol.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/73268630289.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/8b661297d0372c76ff4d9b6c7b307872/zuwubudumuwesirak.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611ed6aee153d---46634124891.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/14259844940.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/e5c5e93baf083d48aa181283ef7a3824/bovodumezep.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/10798233535.pdfIn PDF document text
    • http://classicalgardenfountains.com/uplds/file/fonemikavejukuka.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/b171b3caf5773596d97137aed99ca99f/lulajimokikesodipoxuto.pdfIn PDF document text
    • https://newoptic.mn/uploads/files/6852890746.pdfIn PDF document text
    • http://westleyden72reunion.com/clients/4/46/469dc9162705cbff2d1fbe132f144f37/File/nigabalupajovipexi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=tenses+review+upper+intermediate+pdfPDF link annotation
    • 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_off0000d8a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8A2 18656 bytes
SHA-256: b85cfda16b2059a2c742ebf59a2460ffd33762d758373454ac42d84ec7333e62
font_01_sfnt_off00010959.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10959 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012170.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12170 10708 bytes
SHA-256: c6563c443d0da2aa49e3533fa40adc3c97c02319b428a5d9c49cb4f1bd054f45