Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7af397d5bfc0895…

MALICIOUS

PDF

83.5 KB Created: 2021-09-18 21:23:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 42d7356b960d850d590eb4afe9507989 SHA-1: aafa21d92e34e37129844d32598ee5452ad4ed77 SHA-256: c7af397d5bfc0895ed83a71ac364429c064f6012fadf112e9333e5cd940e1d92
164 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to compromised websites and disposable hosting, suggesting a phishing or malware distribution scheme. The presence of a 'download button' lure further supports this, aiming to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/72208114739.pdf In PDF document text
    • http://xz-brand.com/ckfinder/userfiles/files/fuzivezu.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/161367e519dd75---ganixujudevo.pdfIn PDF document text
    • http://rogersdesignhouse.com/uploads/files/32548709918.pdfIn PDF document text
    • http://china-zub.ru/userfiles/file/garavevureteno.pdfIn PDF document text
    • http://slmj8.com/data/userfiles/files/83305147554.pdfIn PDF document text
    • http://kingkady.com/uploadfile/files/62099985246.pdfIn PDF document text
    • http://struttur-arch.it/userfiles/files/49245729438.pdfIn PDF document text
    • http://aviafond.ru/userfiles/file/mapapanexijaxosar.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/bagoxon.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/gusakibonizixitivijava.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/161452dfb58e99---fisozujupusivuxudasav.pdfIn PDF document text
    • http://yogaschoolofkerala.com/photos/editor/files/lexifugunawikawodiwezo.pdfIn PDF document text
    • https://rais.bg/uploads/file/zafavodonaruj.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408d1a002c3---5801078683.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/zezibepukoboruwube.pdfIn PDF document text
    • http://www.klimavill.com/data/editorfile/kebiwejum.pdfIn PDF document text
    • http://silesiacapital.eu/data/file/zujitijajurulatodapopebev.pdfIn PDF document text
    • http://fapannimario.it/userfiles/files/bawobuzajakejufokebe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=watch+movie+free+on+androidPDF 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_off0000e186.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE186 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f99d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF99D 10588 bytes
SHA-256: 7fcc0d9023e26a8ccf31be58e5ed72c40b61b1a295a1c627aa4d5b764bb1ad34
font_02_sfnt_off000111a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111A6 18340 bytes
SHA-256: f311a1f3f56de2b96d9d1df6d4d3753e99f62154efeecafbbd0eae6d9bd866de