Malicious PDF — malware analysis report

Static analysis result for SHA-256 214927f6cd2ba89f…

MALICIOUS

PDF

73.3 KB Created: 2021-09-16 08:21:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 09b7f0d2ee594c2d97a9618c38dfd771 SHA-1: b6341863c578d283aa5e71aabcdf4747b5c2a164 SHA-256: 214927f6cd2ba89f28be140d76cf710b166e761c74f7a779a3ee5ccc6ad24f00
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://viveironativodevicosa.com.br/ckfinder/userfiles/files/52441311679.pdf
    • http://cuacuonbinhduong.com/upload/files/87136055855.pdf
    • http://sportsgarten.com/editorData/file/23814318897.pdf
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/bd653994d7fd34456952bc95c3118a03/nanejesitomawuguri.pdf
    • http://baltic-rt.ru/ckfinder/userfiles/files/kagejok.pdf
    • http://sportsbettingconsultants.net/cote_dor_import/admin/ckfinder/userfiles/files/90690352735.pdf
    • https://oykufestivali.com/ckfinder/userfiles/files/61433572163.pdf
    • http://diagnosticaedilizia.com/userfiles/files/44692011796.pdf
    • http://neoneofytou.com/ckfinder/userfiles/files/vosevoluwinogukamufege.pdf
    • http://tko.wavedev.net/img/files/files/18694555070.pdf
    • http://electriccityusa.com/images/fck_uploads/file/3746706010.pdf
    • http://mwflower.com/upimagesfile///zimejudafikazidovav.pdf
    • http://cuakeobinhduong.com/upload/files/70493769057.pdf
    • http://polyalpan.hu/_user/file/14117573940.pdf
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7a5817649---12802128595.pdf
    • http://gpe-el.pro/ckfinder/userfiles/files/fewuwamizedivu.pdf
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614104ddb939e---kogiratovuj.pdf
    • https://ncvpte.in/userfiles/file/pujonajetagowafadoxu.pdf
    • http://olgapolyakova.com/files/files/pidekegefim.pdf
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142392c41971---dawulatokekelezizafamo.pdf
    • http://spc1991.com/ckfinder/userfiles/files/55136143273.pdf
    • https://marbletreasures.com/uploads/image/files/70306754631.pdf
    • https://happy-playground.gr/uploads/_uploads/files/biwobumivumugu.pdf
    • http://www.cerel.eu/images/wyswig_images/file/moxidizedizakifojudijewap.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=one+punch+man+mod+apk
    • 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_off0000bcbc.bin
52aaed6637d3dd8cef30821df6bbaa5165bb1c187153727eb43b875485c39821
pdf-font-stream PDF embedded font (sfnt) at offset 0xBCBC 16672 bytes
font_01_sfnt_off0000e7d9.bin
532c578278994d6cba6eba88e1380ea4ee6e366384ecc1e60b8bce0fea5b83fe
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7D9 10492 bytes
font_02_sfnt_off0000ff80.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF80 16792 bytes