Malicious PDF — malware analysis report

Static analysis result for SHA-256 79c8e01c0dfcc2d2…

MALICIOUS

PDF

81.4 KB Created: 2021-09-24 10:28:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 80d1a34ab0a23199ffa7ab8d75cd7f66 SHA-1: d0735cc6a2c7296dbc48edc7899792e06a969695 SHA-256: 79c8e01c0dfcc2d228d1076d2fbb3a928960582b0496fd8c2a64de0c25806ef7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically identified as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and link farm heuristics indicates an attempt to distribute malicious content or phish credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • 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.
  • 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://oniceh.ru/uplcv?utm_term=auto+unfollow+ig
    • https://fiberglasssupplydepot.com/userfiles/files/faridoxa.pdf
    • https://chowdhurytourism.com/ckfinder/userfiles/files/63872617162.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/rdgif08inu8q63kjk4o3niumr7/mulatujev.pdf
    • http://asavn.vn/uploads/userfiles/files/90617810637.pdf
    • http://msdoubrava.cz/foto/images/file/40161091630.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/gf4qaanhj8m2aam9jr29plev03/18156068446.pdf
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146ff9e12677---fexad.pdf
    • http://vektorma.ru/uploads/assets/file/12693834316.pdf
    • http://quick-thailand.com/images/uploads/file/wuvoxetumaxetatamadug.pdf
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/21385515272.pdf
    • http://automsystem.com/UploadFile/file/20210902111345644.pdf
    • http://3e-recycling.ru/app/webroot/filesfiles/bobixaji.pdf
    • http://sculecuacumulator.ro/app/webroot/files/userfiles/files/33880281918.pdf
    • http://thienminhgroup.com/uploads/userfiles/file/vamadefokevubugosusabo.pdf
    • https://h1t-url12shio-turbo.com/contents/files/dumari.pdf
    • http://lex.tj/img/file/88331429480.pdf
    • http://www.tecnobor.com/ckfinder/userfiles/files/18486553948.pdf
    • https://newshieldinsurance.com/demo/gsa/final/images/file/77822828870.pdf
    • https://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/rivukaputedikogaji.pdf
    • http://caogenzhiben.com/filespath/files/20210903045920.pdf
    • http://balletpanov.com/uploads/files/jafafola.pdf
    • http://indemo.pl/Image/files/55950581630.pdf
    • http://phubozena.pl/userfiles/file/95034773959.pdf
    • http://thaymanhinhlaptop.com/userfiles/file/wanisidavetijuru.pdf
    • https://stealthwindow.tw/uploads/files/202109031451144975.pdf
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/mupotinifometosib.pdf
    • 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_off0000dbca.bin
cbc8d8f53771a21801c1379a84f340d29c9ae64b5653002d1b0df79a28999f73
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCA 9996 bytes
font_01_sfnt_off0000f222.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF222 16792 bytes
font_02_sfnt_off00010a34.bin
992c57f67653bd24a22dc6023f15f01952f7549e34d52af4005231721810cc2c
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A34 17736 bytes