Malicious PDF — malware analysis report

Static analysis result for SHA-256 e3832234b3f158bc…

MALICIOUS

PDF

68.4 KB Created: 2021-09-28 20:55:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2cba36054dc55ed6a5719f1ff9023e76 SHA-1: ec571a3fe9215af710432c233bec6e58810afe01 SHA-256: e3832234b3f158bc28fd0a60d379ce4d1d441e02579038479a5f6ea4bf3a03ec
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites. The heuristics indicate the PDF acts as a link farm, with many URLs pointing to potentially compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://baodieptailor.com/uploads/2021-09-10/images/files/91324677953.pdf
    • http://jinruily.com/UploadFile/file/20210905112835320.pdf
    • https://tomorrowhubs.com/upload/users/files/zibinagipu.pdf
    • https://cukimentescukraszda.hu/files/files/wazawesibuzuvigesurema.pdf
    • http://twilaw.com/files/files/bigaxap.pdf
    • http://podhoru.cz/userfiles/file/ragobexika.pdf
    • http://allycatering.com/userfiles/5115681015.pdf
    • http://meadescafe.com/userfiles/file/vivikekuvosusefapamuzuv.pdf
    • http://www.ocptecnology.com/admin/uploaded/fck/file/1378977194.pdf
    • https://www.singaporemedicalclinic.com/ckfinder/userfiles/files/9930762446.pdf
    • https://bosgo.mn/uploads/files/limelonokefof.pdf
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161426e0f63666---zogowopisivibukumapudo.pdf
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/a0cks68djgcg3bl7uqmcon9jq4/33582311919.pdf
    • http://maturitni-ples.eu/UserFiles/File/4452724064.pdf
    • https://chinese-wall.tw/upload/files/tepalomuwoxas.pdf
    • http://ziva-muzika.cz/files/file/81815044068.pdf
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a438800a1---93862961297.pdf
    • https://membermimpi.com/contents/files/fepowe.pdf
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kazaleginekurufaro.pdf
    • http://steinemann-ag.ru/xokezofade.pdf
    • https://termokingbt.com/ckfinder/userfiles/files/kijinap.pdf
    • http://giustizianuova.it/userfiles/file/51736561498.pdf
    • http://oldmotorsclub.com/files/file/12254715928.pdf
    • http://speed-r.com/js/upload/files/linimubopimuzipokax.pdf
    • http://mfo-fond.ru/ckeditor/ckfinder/userfiles/Images/files/55823205832.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=morning+dirty+jokes
    • 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_off0000afc3.bin
0ad7dd58acfc444d2e3abc8f4f755eab6aba3bd06367069c2e546d36f5578cce
pdf-font-stream PDF embedded font (sfnt) at offset 0xAFC3 14596 bytes
font_01_sfnt_off0000d43c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD43C 16792 bytes
font_02_sfnt_off0000ec53.bin
d129ed73b91e679d309a81f6f5aa6435730117d6fefc356b1af0bdee12589049
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC53 10544 bytes