Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8d7a6aae845734c…

MALICIOUS

PDF

84.1 KB Created: 2021-10-08 05:53:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9066ac26453eceb5ca874bad7aebfadf SHA-1: 447ecf1fc1a337a769c25c2add1fdb9a3da7e740 SHA-256: a8d7a6aae845734cd13c5164bdbb8c38bad01056b51a71acd4e6eed8ae3d4619
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS uploads or disposable hosting. The embedded URLs suggest an attempt to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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.
  • 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://resheto.ru/users_images/fck/file/57066057182.pdf In PDF document text
    • http://starroadchina.com/userfiles/file/50702401026.pdfIn PDF document text
    • http://didopack.com/files/7177979793.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/161348ddc67cf6---73841131948.pdfIn PDF document text
    • http://www.psoevalledeabdalajis.es/ckfinder/userfiles/files/84931969823.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/7078048330.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b6c6676bd5cbe760df693778e8c13500/wagoxitelaxibuxaliduwovuk.pdfIn PDF document text
    • http://hun777.hu/_user/file/39463045201.pdfIn PDF document text
    • https://tbsva.org/Upload/files/20210906221311.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name/files/xudunixowe.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/kejivobugazazonekipudob.pdfIn PDF document text
    • http://orderkai.com/uploads/files/subozimo.pdfIn PDF document text
    • http://denge.aero/upload/files/dibexovo.pdfIn PDF document text
    • https://tahitotfalu.hu/ckfinder/userfiles/files/89361818764.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/gajevukuraxobomujopusa.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/f7e9ec7e4223070718de9df352e28aa4/91536042143.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109130157505391.pdfIn PDF document text
    • http://veterinariacasettamattei.it/userfiles/files/11940561697.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/81d287d2aaf03b60dd6b3298b2df7532/15890635355.pdfIn PDF document text
    • http://1111.morefriendship.com/upload/files/20704343656.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/161590d1a34344---25761685903.pdfIn PDF document text
    • https://rmp-familienanzeigen.de/cms/files/jonugewiwujenarokusip.pdfIn PDF document text
    • http://nemalipics.com/kalusamawatimagawulixarim.pdfIn PDF document text
    • https://blgjad.com/upload/files/rezofojiwusurotomajutite.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=are+boiled+eggs+good+for+upset+stomachPDF 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_off0000db45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB45 11184 bytes
SHA-256: dadd93f11b01d61dbe8a0c39221a7aaf71aa4ff787c67b6adf5fd43aa256f215
font_01_sfnt_off0000f505.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF505 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010d17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D17 20768 bytes
SHA-256: 9fd2706bfa6c9093f0055bd9b22ee2e870c0e84d4c879488cb774bf6cea8d96f