Malicious PDF — malware analysis report

Static analysis result for SHA-256 40d78f1fca24638c…

MALICIOUS

PDF

90.9 KB Created: 2021-09-21 11:00:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a4b0bde0b3dac82ed9108b0c18c28af9 SHA-1: 5edc189ef33fb494c2063d2710816fbbe127a6d8 SHA-256: 40d78f1fca24638c5d2100341867db3241d6f16e57dfc8ac81154846420b1ba8
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code or redirecting users. The presence of multiple external URIs, including those hosted on compromised CMS uploads and disposable hosting, indicates a link farm designed to obscure the ultimate destination. ClamAV also detected this file as Pdf.Phishing.Trojan, further supporting a malicious intent.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.4043

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ruizhishengwu.com/uploadfiles/file/060426518148.pdf In PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1614912e601bf8---rapexanunitijuzabe.pdfIn PDF document text
    • https://mcq.bmtinhoc.vn/InteriorWeb/images/images_news/files/gezanagukapupedono.pdfIn PDF document text
    • http://dermatologomiguelgallego.com/miguel/fck/file/45861312130.pdfIn PDF document text
    • http://skulpt.in/admin/uploads/file/pipoxovamimixaxiwani.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/bodereje.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145b5602a078---53572121380.pdfIn PDF document text
    • https://edgecs.com/documents/80827151195.pdfIn PDF document text
    • http://evola.it/userfiles/files/pugisoxobufominedudoj.pdfIn PDF document text
    • http://conhantaoankhanh.com/webroot/img/files/16916765783.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d5701c2cd4---bigizi.pdfIn PDF document text
    • http://fuyu.010bi.com/ckfinder/userfiles/files/10867715339.pdfIn PDF document text
    • http://gesundheit-im-blog.de/userfiles/file/tixivigomeroweda.pdfIn PDF document text
    • http://webinaris.training/ckfinder/userfiles/publics/files/sewewu.pdfIn PDF document text
    • http://bastola.org/userfiles/file/giwekelixifuxizojidili.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/tuvibizikasan.pdfIn PDF document text
    • https://kemxoithanhhang.vn/app/webroot/files/images/pages/files/5707761134.pdfIn PDF document text
    • https://akanaymatbaa.com/calisma2/files/uploads/zifama.pdfIn PDF document text
    • http://kimhoatra.com/upload/fckimagesfile/kolobagudavipisosim.pdfIn PDF document text
    • http://nwatchonline.com/userfiles/file/wigosobidavujez.pdfIn PDF document text
    • http://mackyz7automotive.com/js/upload/files/74612852824.pdfIn PDF document text
    • http://www.la-rocca.pl/app/webroot/files/files/jivowunozuziwuvu.pdfIn PDF document text
    • http://tetrafluoro.com/upload/files/79792681222.pdfIn PDF document text
    • https://wigs4less.net/nbloom/fckuploads/file/taluxizibekag.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141cb4b176f3---61178388195.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=all+anime+fighting+apkPDF link annotation
    • 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_off000106d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106D5 10488 bytes
SHA-256: a97b44b193cc44f1015b479df1a5a0705a14533efa964eb46bd83c1028ee9fcb
font_01_sfnt_off00011e77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E77 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013689.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13689 18320 bytes
SHA-256: 61071af15d339e635b92377801db03aa03caa29351a41d81ef100ad3484878b9