Malicious PDF — malware analysis report

Static analysis result for SHA-256 77e5839af154390e…

MALICIOUS

PDF

75.2 KB Created: 2021-05-22 03:47:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 635023e620490a73f0cb3415262f2d50 SHA-1: 52dd019fc22314c52fa8022f1501be5b08b50a05 SHA-256: 77e5839af154390e8bc3000772421528d584e339a555dd8aeee25d7d13ee5c3a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to compromised WordPress sites and disposable hosting, suggesting it's part of a link farm designed to distribute further malicious content. The document body, though partially corrupted, indicates a lure related to educational worksheets, likely to trick users into downloading malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://zlatartopalovic.rs//files/lububuguvefifajefizulalu.pdf In PDF document text
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/450237e75502fbb0b2adc4cfdd0848d6/mevoraraki.pdfIn PDF document text
    • https://adsbudget.net/userfiles/file/27336524446.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/68491293027.pdfIn PDF document text
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/fba3905049d8963e2054e4bfca57de67/xoxidosiwomujafaxugar.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160850d9357ede---letodusufuvijite.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/majufewurogasasa.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/16092b1aeb69cc---5475247628.pdfIn PDF document text
    • https://loctra.net/userfiles/file/nezirubasigajaz.pdfIn PDF document text
    • https://africanresearchcenter.com/userfiles/file/32860400905.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16072dc76163a0---vefigutedilununupoziga.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/4c142c71ade401129b72f9ec2c9b0533/5237284315.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607adaf3e0763---livew.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/ps600kofbo2kbgb04v4k2u519v/xiliteniganadorixosifuf.pdfIn PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607522d0d542f---95319399927.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/7854038716.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/9c50045fecee3d7893752d1bd50bcd52/52387525349.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=past+tense+of+irregular+verbs+worksheets+for+grade+3PDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8F3 5572 bytes
SHA-256: cc06b043a7b50b95772c88638bd716343e4355dfc7f56ea6d986e077c70717dc
font_01_sfnt_off0000ebee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEE 10884 bytes
SHA-256: b69a4c2ef1f52135bda21bc3868fbba9373ad8e7852778df80f63fc6b8852005
font_02_sfnt_off00011132.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11132 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176