Malicious PDF — malware analysis report

Static analysis result for SHA-256 779eab062904ad32…

MALICIOUS

PDF

152.2 KB Created: 2021-05-10 08:55:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 9f61f928990d32000e0d503761ca15b3 SHA-1: 09609dd2b685055a7051aff5e3be200e8eecf38a SHA-256: 779eab062904ad32c2043ed0ce490b41a89137840db032f4582220a023ae6bb9
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external resources, many hosted on compromised WordPress sites, suggesting a link farm designed to host malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading and executing a payload, such as the 'vcredist_arm.exe 64 bit' mentioned in the document body.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://pelesiuvalymas.lt/i/File/nemubaxolaberobew.pdf In PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160987b2010d1a---91157774449.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160796b5f0ee14---85266178907.pdfIn PDF document text
    • https://www.kalirich.com/wp-content/plugins/super-forms/uploads/php/files/kcdqhu6ibmobscea9pb0hmctb0/93473123014.pdfIn PDF document text
    • http://arci-mp.fr/admin/File/febevasezam.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1608a176039b88---88025911615.pdfIn PDF document text
    • http://mousike.it/img_ins/files/21424705859.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/au55hg0oov4lk82nggsblba4q0/31508928632.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084bed218608---63146396933.pdfIn PDF document text
    • http://supermarketdv.ru/files/file/bazufikujuwegotifojuni.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f650a6c3fa---jixojebubuvovu.pdfIn PDF document text
    • https://islandsvefir.is/wp-content/plugins/super-forms/uploads/php/files/7ad16ao0745ifqf0c80es2kl1s/4337568287.pdfIn PDF document text
    • https://martybermanassociates.com/wp-content/plugins/super-forms/uploads/php/files/c80e002df12096e1925bb5d405da3247/91373561514.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c89f15bd5f---goxudi.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/5807bded68cbcac7595e7cdc4784ee2b/34817832141.pdfIn PDF document text
    • http://aptchasers.com/FCKeditor/userfiles/file/76088995166.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/86da6hf00je11j7924li30t9vp/31312553583.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=vcredist_arm.+exe+64+bitPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off0000e14c.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xE14C 108340 bytes
SHA-256: 13fe1de2b4ffcad5fd9cff7f077b8836cfe0c3a538cc9d0b59e5a0bd12c6b65f
font_01_sfnt_off00021ace.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21ACE 5532 bytes
SHA-256: 13569948435d708b4f9d3ecada3d535c35026cb84b64b82035098d432e1b9de3
font_02_sfnt_off00022da1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x22DA1 10364 bytes
SHA-256: e8687380a2e7ab54390a2f9fdd339aa6bbb7c2ef970d88b327f2d9ad4c4db98b