Malicious PDF — malware analysis report

Static analysis result for SHA-256 d55cd8276ea80b9c…

MALICIOUS

PDF

76.8 KB Created: 2021-09-21 02:12:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8be421262e776957be3fcb82b51fd742 SHA-1: b5e0f702c603fe4fea5afa60f50b1e1d59ac6b51 SHA-256: d55cd8276ea80b9c45b0cd9955733c2b38943696a0adc2c0302d25b924255051
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious documents designed to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/5c4c26d1ea1fae021ff6827edf00c93f/patupenujid.pdf
    • http://philboyd.com/91838499819.pdf
    • http://synhbio.com/upload/files/11205532938.pdf
    • http://szolnokepul.hu/userfiles/file/55024584356.pdf
    • http://basumati.com/app/webroot/ckfinder/userfiles/files/5120638148.pdf
    • https://pincodehub.in/userfiles/file/139320354.pdf
    • https://morganmethod.com/ci/userfiles/files/namotaketodarelokizawex.pdf
    • https://linker.tw/files/51333508777.pdf
    • http://ericshartman.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/20728648442.pdf
    • http://otoozevran.com/resimler/files/69555912060.pdf
    • https://alzubidi.com/userfiles/files/zebabedepuguzedekux.pdf
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1614289a2c477e---jilodanimoluwidu.pdf
    • https://confeccionesruiz.cl/UserFiles/File/18825668645.pdf
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/10393890211.pdf
    • http://avandcie-energy.fr/ckfinder/userfiles/files/xadunon.pdf
    • http://clarksville.net/wysiwygfiles/file/75233739272.pdf
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/cbcf7237f43815884087a07aa65c7052/70846844934.pdf
    • http://cosmoscm.com/contents/files/72606063851.pdf
    • http://rollfactorytogo.com/uploads/files/rezitarorore.pdf
    • https://harshahometutors.com/uniformkontakt/userfiles/image/files/sagute.pdf
    • http://escuelasfutbol8.com/docs/files/tedoroxakewos.pdf
    • https://bomando.bomsolar.com/uploadfiles/files/nopexiwovazutaxajuwi.pdf
    • http://wecans.net/_UploadFile/Images/file/varosagug.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=how+to+find+the+pattern+lock
    • 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_off0000ca1b.bin
f30a590e665e2b65d27ec568c26e7bbf4c458c1446d7a38c13d8eace6e71781d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA1B 16680 bytes
font_01_sfnt_off0000f55a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF55A 16792 bytes
font_02_sfnt_off00010d71.bin
f4168f5ebe5378a66fc2d5f8aee822d692a2b5afe5b0b748fc80fb00db7fca43
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D71 10720 bytes