Malicious PDF — malware analysis report

Static analysis result for SHA-256 c64a6d2cb2de5740…

MALICIOUS

PDF

68.0 KB Created: 2021-09-28 07:13:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2b3dba938fd0e1c1d77428a118edb3b4 SHA-1: 1b17969ff003c706f6c6bf58a3f3064191ebf77a SHA-256: c64a6d2cb2de5740d3154488cbf02e069785ef3d0cc641392a01b61ce12843f5
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to compromised WordPress upload storage and other disposable hosting sites, suggesting an attempt to distribute further malicious content or redirect users to phishing pages. The ML classifier strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 6

  • 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 https://wangwangcamp.com/uploads/files/202109181159185875.pdf In PDF document text
    • https://xylemleads.com/userfiles/file/69141309628.pdfIn PDF document text
    • https://kanat.com/upload/ckfinder/files/fosixuna.pdfIn PDF document text
    • https://baohohoanglong.com/userfiles/file/kejoxifedim.pdfIn PDF document text
    • https://adikkeempat.com/contents/files/12552360487.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/gikozubedubunub.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/q6562avr5fs7a313nj7tufv520/puwatevizanitalek.pdfIn PDF document text
    • https://learningsolution.ca/userfiles/files/pisidevufazokevanetup.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/18086893403.pdfIn PDF document text
    • https://corcreation.twbiz.me/data/fckeditor/files/20210925_215029.pdfIn PDF document text
    • http://protok.pro/upload/files/84273588869.pdfIn PDF document text
    • https://sangolongphuong.vn/longphuong/news/files/miguxakodebipujuneg.pdfIn PDF document text
    • http://www.ccengis.be/applications/ckeditor/addons/ckeditor/ckfinder/userfiles/files/61005611472.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b045d50cd7---82357631891.pdfIn PDF document text
    • https://cpc-serbia.org/js/files/8476875857.pdfIn PDF document text
    • http://mosjob.ru/images/file/wikovikejab.pdfIn PDF document text
    • http://kfnmdg.com/upfolder/e/files/20210927211506.pdfIn PDF document text
    • http://style4.allwebeasy.com/userfiles/files/99370129412.pdfIn PDF document text
    • https://pqclass.kr/imgs/file/tijatowedonenanivi.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/16143b90cb2601---82432697355.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=the+silence+of+the+lambs+2+full+moviePDF 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_off0000aaca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAACA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c2dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2DC 15108 bytes
SHA-256: 86815b7493fcfc4457a895fb623f9c14b700e3edde0c092394a73885d1a3431d
font_02_sfnt_off0000e94c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE94C 10888 bytes
SHA-256: b8be79f8fc47362e9c0b13a0912d755debe312bacd90ff79713eb5bede18dfc5