Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a1cb1d0762aa089…

MALICIOUS

PDF

91.2 KB Created: 2021-08-30 09:06:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 21916e857020af7c60feb37d65978278 SHA-1: ea1613f1f26096dcc38dd886f926022e3516f0d1 SHA-256: 7a1cb1d0762aa089d8f4c6274493d5a6b02542f114c94e0eeb7c37e0206d2c78
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are consistent with techniques used to redirect users to malicious sites, often as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://cructi.ru/uplcv?utm_term=8th+maths+solutions+pdf
    • https://lee-trading.tw/archive/upload/files/51353417112.pdf
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac58b0a43e6---wobupidemizekexoguwofakap.pdf
    • https://worldmedglobal.com/userfiles/files/mujevupamafizaluvebi.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b14e7d484c3---feloxe.pdf
    • http://f-okinawa.com/img/tmp/files/41434919577.pdf
    • http://www.awakohchang.com/image/upload/File/2276251264.pdf
    • http://decaiyun.com/upload/file/210724065808357594fss8tkmckz40.pdf
    • http://arcomproltd.com/userfiles/file/luvomafikigaxewufolususod.pdf
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16124a7a08e6f5---wiboxowax.pdf
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/561918d1d169192de1998d36342fc3f2/posafenop.pdf
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076f992a85f9---miwosanefez.pdf
    • http://aitrans.org/UploadFile/file/F1202105170744504251.pdf
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9a3421d31---22774654019.pdf
    • http://mojahotels.com/ckfinder/userfiles/files/jefugerujugo.pdf
    • https://silverlabpupsforsale.com/userfiles/files/miwewoteguje.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/6042475cc3f060684902d2f190a243ce/duguziwabanuzik.pdf
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/9llifofq5ahgt571mlsns5vrvl/56568193494.pdf
    • http://huntland.hu/upload/file/dozifexumazefe.pdf
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/2dabb90a20b9e7179728308f0941b971/83222322121.pdf
    • https://skinrepublic.vn/webroot/img/files/voxarokivupefaxikefe.pdf
    • http://accessiblevehicleservices.com/userfiles/file/fiziwesoxolamorapuxofa.pdf
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ef55eb5c20---47446571951.pdf
    • http://synfarm.com/upload/files/xetewatetuvidagawoxozul.pdf
    • 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_off0000fdfc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDFC 16792 bytes
font_01_sfnt_off00011613.bin
cc1850e9c35a42e9648db3b801d9498c48873f3415589cc078bcb1bc2f286088
pdf-font-stream PDF embedded font (sfnt) at offset 0x11613 10744 bytes
font_02_sfnt_off00012e88.bin
976c34a40495c0bb11e71c1ed419a8ec47fe547695cec0f8799d774081ae2914
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E88 18320 bytes