Malicious PDF — malware analysis report

Static analysis result for SHA-256 2cda186528978c50…

MALICIOUS

PDF

82.2 KB Created: 2021-09-18 12:58:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: af61243b71967ae026a916b2f1b8657b SHA-1: beb338bc9f64c279aa442b3dac408cfdba7eead1 SHA-256: 2cda186528978c508324799a20996bf579fb3d1f108efeb610b93f13178592a3
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to various websites, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the document's purpose as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://qualityroofinnandsuites.com/nbloom/fckuploads/file/54717457.pdf In PDF document text
    • http://bijverhoeven.nl/uploads/files/zesidewirena.pdfIn PDF document text
    • http://www.klccpa.com/userfiles/file/In PDF document text
    • http://kleinschaden.expert/userfiles/file/gotisuba.pdfIn PDF document text
    • https://fong-cai.com/upload/files/44306429048.pdfIn PDF document text
    • http://www.hkimm.hk/_bin/ckfinder/userfiles/files/xikoloroniso.pdfIn PDF document text
    • http://pensionpoint.cz/userfiles/files/69939583575.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/fidokuneka.pdfIn PDF document text
    • http://caudafotografia.com/userfiles/files/zikomanoveri.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/2e385bbab31abb2034d58d5b2adca058/nigajinapob.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/10761178272.pdfIn PDF document text
    • http://ccsilver.kr/files/fckeditor/file/1465121232612ece408aa62.pdfIn PDF document text
    • https://aspirecambodia-edu.org/userfiles/file/niwiziwogeroxameg.pdfIn PDF document text
    • http://www.farmaciabergua.com/userfiles/files/89679543297.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/58597d4023f01718824436783ac5d75d/90494074804.pdfIn PDF document text
    • http://debrecen.varosom.hu/userfiles/files/52428190554.pdfIn PDF document text
    • https://sergiomauri.com/images/file/72889727480.pdfIn PDF document text
    • https://lotte-ppta.com/beta/assets/file/31706339562.pdfIn PDF document text
    • http://hissekurban.com/resimler/files/dazilu.pdfIn PDF document text
    • https://yptea.com/data/fckeditor/files/teran.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/a33721d69772a1e63488ff877a9a3e75/lulukezup.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7af4ae6ee---16987403370.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/161366acf4828b---tefagik.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/povalagudefaku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=longtv+karaoke+apkPDF 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_off0000d53d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD53D 20676 bytes
SHA-256: c3692841449ffa8a53275ce473b9240d60ecdc729d6df231f3c8078ca0e64ab9
font_01_sfnt_off00010c0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C0F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012426.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12426 10236 bytes
SHA-256: 7aa9c1dc09641dbcd6eae8c791ae03379cd941be01448669aaf7b8d87a3acc8a