Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfef5ca96f525046…

MALICIOUS

PDF

77.0 KB Created: 2021-09-24 21:27:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a522b54c6c75a8af3378bb85dd9f82c9 SHA-1: dd3337c00d4b1d5019cb6f666bbc0ce26ad9c11a SHA-256: cfef5ca96f5250460c4630ce7fa4a79aa1f57248029fe8f3642ad926a8ef3120
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs, several of which point to compromised CMS upload directories, indicating a potential phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. No scripts were extracted, but the structure and URL analysis are sufficient to infer a malicious link farm attack pattern.

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 http://ibookingkr.com/FileData/ckfinder/files/20210911_12FF1F5228A2AFFC.pdf In PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/fca4cdcdca4d0ee621e3cac171ac42ec/10752878324.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16143446a170e1---19477935397.pdfIn PDF document text
    • https://dodatkireklamowe.pl/web/uploads/files/16918137253.pdfIn PDF document text
    • http://radis-rrl.ru/userfiles/image/86994567246.pdfIn PDF document text
    • https://movimientofamiliadejesus.com/images/uploaded/file/gaxakeb.pdfIn PDF document text
    • https://borsalino.ro/imagini_ws/25522988393.pdfIn PDF document text
    • http://baovethanglongmb.com/upload/files/xurukiwetugasaj.pdfIn PDF document text
    • http://gzlmjx.com/data/home/bxu2343160066/htdocs/uploadfile/files/35363881337.pdfIn PDF document text
    • http://esrafisek.com/images_upload/files/lowelotubusawigujelulos.pdfIn PDF document text
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/42033241108.pdfIn PDF document text
    • http://sladkiy-ostrov.ru/userfiles/files/ziwajovebuwo.pdfIn PDF document text
    • http://rpsbchamber.org/editorData/file/62163136869.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/ridopujekudumufix.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/tibif.pdfIn PDF document text
    • http://xn--38-mlcqjbufcz6h.xn--p1ai/userfiles/file/61549733055.pdfIn PDF document text
    • http://immopolignano.lu/images/woxazizodegutadis.pdfIn PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/xabanexepatexobeg.pdfIn PDF document text
    • https://lomasdelaweb.com/userfiles/2008.09/file/zezosovuvetefavexukol.pdfIn PDF document text
    • http://ccadl.com/files/20210918092657.pdfIn PDF document text
    • http://talesma.com/E/file/kitiladisabitufifi.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141c1c879b12---57395732177.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/baxedovakareje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=how+long+can+u+leave+cooked+chicken+in+the+fridgePDF 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_off0000c39a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC39A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBAC 18828 bytes
SHA-256: 69cb707e03c17b92c578f58f0fc174e842b04d8179d98b19b3b09e5f56f1c861
font_02_sfnt_off00010c92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C92 10924 bytes
SHA-256: 89d6adb63122983e09b1646a58c71d9146b0ecc0e9121d01d69dd84015dbc9ec