Malicious PDF — malware analysis report

Static analysis result for SHA-256 97dd9939cd15a94b…

MALICIOUS

PDF

77.7 KB Created: 2021-07-04 11:30:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bdff07ff9767a1950683a5fa4fa71c7a SHA-1: 0796f3ed855c6f839bdfa375335ea940b97d4e89 SHA-256: 97dd9939cd15a94bfb80e6f547c52b4ed72a6b3219320b751464875a4cfa2977
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, pointing to numerous compromised CMS uploads and disposable hosting domains. The embedded URLs suggest a phishing or malware distribution scheme, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://gorisum.net/fckeditor/upload_file/file/26939636664.pdf
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/2t871mranneq8u97518cb9m28k/88791331283.pdf
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/1g33ca28t6q1oie9dugl37n2md/kavujujavu.pdf
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/aes34og2gqslajgpe1fjjtco3u/sijowabirixed.pdf
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16098768d5c19e---55744542242.pdf
    • https://iqmuseum.mn/uploads/files/golajigofukiduga.pdf
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/c7915974c8237500c0929b5be1e0efb7/49368404922.pdf
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/d76068525f38eed19ee96423b0fb5516/rokuzolilajutawas.pdf
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd44ad2ffd---wufoxasazivigiz.pdf
    • https://aimhc.com/userfiles/file/menixiwejumozibo.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c75f4a6e94---zajilavus.pdf
    • http://kaies.cn/upfiles/21062100165547258232rhi1.pdf
    • http://dush-kz.ru/uploads/fck/file/19599750284.pdf
    • http://akinmedikal.com/uploads/file/kajinotonugozup.pdf
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/fa4akfik5dmpphf208t6n3p1g8/61567349236.pdf
    • http://alemotta.com/resources/original/file/tumejizolinukutukub.pdf
    • https://elitstroycraft.ru/source/file/19992616740.pdf
    • http://ankamet.com/userfiles/file/22226028610.pdf
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/mrmfb4lo0f7fglf4gf921niqua/88668784415.pdf
    • http://thedreams.cz/files/rebijadimu.pdf
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/c7ffd471d4876b8258f96e20ad54eda4/mudujedorevamomelixigegof.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=signing+a+letter+with+yours
    • 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_off0000ccfd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCFD 16792 bytes
font_01_sfnt_off0000e50f.bin
d912156375fe662345a73cc84f8599c9e9aaae5ec68e04799e2b0e511df0da18
pdf-font-stream PDF embedded font (sfnt) at offset 0xE50F 16932 bytes
font_02_sfnt_off00011104.bin
2982d0784af8be2b4909cd79b05e6fc89298adb4b4580de0b71c5bebec1f970b
pdf-font-stream PDF embedded font (sfnt) at offset 0x11104 10760 bytes