Malicious PDF — malware analysis report

Static analysis result for SHA-256 15bffc963af1db93…

MALICIOUS

PDF

83.6 KB Created: 2021-09-13 07:11:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a53d753940a98b85700e4d6cb4e892c8 SHA-1: 6b33702ff8d85cd398f6c53018c28be5c810bd50 SHA-256: 15bffc963af1db93ad0c9661b96bae80322e8c84b54dfd515d055f09a7f2246e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to disposable hosting or compromised CMS uploads, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://grabnerestriche.at/tadadogu.pdf In PDF document text
    • http://isystem.hu/userfiles/file/80151279279.pdfIn PDF document text
    • https://beaszemin.com/files/gepez.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/99f1f000a0d01751a9cde873dda9e57a/kamonubimixogu.pdfIn PDF document text
    • http://deforma.it/userfiles/files/weniziwijokosudutixotab.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/lilowerigij.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/161392919b3891---fejezivifarelozutex.pdfIn PDF document text
    • http://eraldocomo.it/userfiles/files/tipitivivexulezubuxad.pdfIn PDF document text
    • http://ulrike-mayer.de/userfiles/files/nekamomum.pdfIn PDF document text
    • https://motecx.com/images/file/42902811826.pdfIn PDF document text
    • https://adtw1.com/ckfinder/userfiles/files/suvedemumu.pdfIn PDF document text
    • https://devcons.org/uploads/userfiles/files/62724253162.pdfIn PDF document text
    • http://riccaassociati.eu/userfiles/files/zikilug.pdfIn PDF document text
    • https://ceylanotel.com/firma/files/dusadogemofi.pdfIn PDF document text
    • http://yingtailong.com/upload/file/210909165939334874lzn2knlreyvm.pdfIn PDF document text
    • http://tavio.su/files/file/mepotelelifunemalo.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa8958daf7---soxotijiwebifazukake.pdfIn PDF document text
    • http://sanruou.com/app/webroot/uploads/files/44407766768.pdfIn PDF document text
    • https://underworldgear.com/upload/users/files/97947788663.pdfIn PDF document text
    • https://danielstrehlau.com/userfiles/file/52015058369.pdfIn PDF document text
    • http://xn--o39a91gvwm83kbsn.net/FileData/ckfinder/files/20210912_D8BD8F5132329EAC.pdfIn PDF document text
    • http://siamsnail.com/media/userfiles/files/18435876871.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/razugaputeseso.pdfIn PDF document text
    • http://mgtuae.com/uploads/file/88434626576.pdfIn PDF document text
    • http://gildiamasterov.ru/userfiles/file/lijugoganeter.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/49817788190.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+activate+voicemail+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_off0000e12a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE12A 18156 bytes
SHA-256: 40b07f7d406965df7d05af1ab01ce6da8cefa5b0a918e586d47203ff936fe2ce
font_01_sfnt_off00011048.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11048 10508 bytes
SHA-256: aba89b2eaa24fbb658e6f3d894197ea8a33a73c1559b533b6b12f35b34a3e5d6
font_02_sfnt_off00012827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12827 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1