Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7461bc742375750…

MALICIOUS

PDF

80.8 KB Created: 2021-09-19 01:56:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9dccecad6377f8b2e937fb538121c017 SHA-1: f8ab39c3d766ee591d71c0b1d856236995565498 SHA-256: b7461bc7423757506489fc751687e10c7f08b0f9c4d44a90cfbb0db20e8271c3
134 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of numerous external URIs, including one with a 'play store app download' search term, suggests a phishing or social engineering lure. The heuristic 'SE_DOWNLOAD_BUTTON' further supports the idea that the document is designed to trick the user into clicking a link to download a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cructi.ru/uplcv?utm_term=play+store+app+download+and+install+free+for+android+mobile+free+download+download PDF link annotation
    • https://bjjewels.net/nbloom/fckuploads/file/figifolikonasilupelorad.pdfIn PDF document text
    • https://newshieldinsurance.com/demo/gsa/final/images/file/pukoxegakulo.pdfIn PDF document text
    • http://vocal.bpv.su/content/files/files/dutesuzererip.pdfIn PDF document text
    • https://amzentransportationindustries.com/admin/imagetemp1/file/dazezokujobefun.pdfIn PDF document text
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/65510304224.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/a6b3b614d07218a8f8677e95965cc522/55956900124.pdfIn PDF document text
    • https://rawoctane.com/uploads/file/52684647408.pdfIn PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/19283181516.pdfIn PDF document text
    • https://dcimx.com/files/43905245400.pdfIn PDF document text
    • http://cuakeobinhduong.com/upload/files/xikilodulalezofobamefelu.pdfIn PDF document text
    • http://anpharma.net/upload/files/wixajagavogunigid.pdfIn PDF document text
    • http://linza-market.ru/upload/files/xatajef.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109061451365583.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/banufok.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/202198210416988.pdfIn PDF document text
    • http://zezoalza.com/ckupload/files/92222331253.pdfIn PDF document text
    • https://yuanfuconstruction.com/ckfinder/upload/files/12648961352.pdfIn PDF document text
    • https://karpzbeldowa.pl/uploads/userfiles/files/16614497795.pdfIn PDF document text
    • http://flapboxes.com/userfiles/files/2983805661.pdfIn PDF document text
    • https://ckfinder.pamlskovnik.cz/ckfinder/userfiles/files/limevakovenukibusigowon.pdfIn PDF document text
    • https://onlineadda.net/ckfinder/userfiles/files/38662332622.pdfIn PDF document text
    • http://goref.ru/files/file/13761034060.pdfIn PDF document text
    • https://playindiano1.in/ckfinder/userfiles/files/fuxatabobulomijesebuzum.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/defupajebalupupanigef.pdfIn PDF document text
    • http://tcgardening.com/userfiles/file/2021091815494873499.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_off0000d7b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B0 16572 bytes
SHA-256: 03dd89c564e0c5cb6a738a1ca72500ef1026bb65911ffdc541f8a2326ee984b8
font_01_sfnt_off000102a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011aba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ABA 11000 bytes
SHA-256: b7c5085801ad61d9670ba98c47e8af8b21e57165a8a35d1db285add6972ee194