Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5acb3c239784321…

MALICIOUS

PDF

90.0 KB Created: 2021-09-24 02:21:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 402b5c3254d861770e6f81e2d3e66a3c SHA-1: 55770a374c935e5aa51c538a203e772fd062c750 SHA-256: c5acb3c2397843212c9ae7d82cda64eabebfa3d8372f83551fcff99baf745b28
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised CMS uploads and disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://allytemp.ru/uplcv?utm_term=western+movies+free PDF link annotation
    • https://indicaperu.com/userfiles/file/kapoxunopusoxafirikew.pdfIn PDF document text
    • http://temple.mo/userfiles/file/lutolufa.pdfIn PDF document text
    • http://viettranslators.com/webroot/img/files/wexojuviga.pdfIn PDF document text
    • http://stphilomenaonline.org/userfiles/file/75414650896.pdfIn PDF document text
    • https://siliconautomation.com/userfiles/file/41138528891.pdfIn PDF document text
    • http://dpsszczytno.pl/photo/file/zabodinafaveserisomok.pdfIn PDF document text
    • http://mishor-uvk.com/uploads/files/jomomavomiboxizizeg.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/70d651c0d5ad5282c73de3b1c5bc0965/tifomejafujaledabikodeke.pdfIn PDF document text
    • https://silky.ae/images/bulk_images/files/56728090588.pdfIn PDF document text
    • http://cephedanismani.com/images/pages/file/gilexadiloboniguguni.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/40620996089.pdfIn PDF document text
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/72897947391.pdfIn PDF document text
    • http://tns-china.cn/editor_upload_image/file/76234731467.pdfIn PDF document text
    • http://rvhifi.cz/files/file/74235092375.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16140584917880---83645249910.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/j86q18bbce9ie74emjnhquhr06/watesixagoperesutut.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/14593563819.pdfIn PDF document text
    • https://www.agcontraincendios.es/ckfinder/userfiles/files/zitokozabefudef.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/37296733763.pdfIn PDF document text
    • http://alvitraders.com/files/63170732896.pdfIn PDF document text
    • http://elijasprojekts.lv/files/file/50378710302.pdfIn PDF document text
    • https://qud27rxl1-k61l.com/contents/files/50496969225.pdfIn PDF document text
    • 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_off0000ff27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF27 17228 bytes
SHA-256: d2dd37f67c3dfb87fe61b01d5374bbd8ec5246c2d0d53bc4ad2d42820a8a3ed4
font_01_sfnt_off00012bcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BCF 10224 bytes
SHA-256: 5dd316473b5824371fbdaee876497ebebe9739b409d69fbc843ba6f919670f60
font_02_sfnt_off000142c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1