Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff4d9ae3b450bf5a…

MALICIOUS

PDF

77.3 KB Created: 2021-09-16 14:22:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f588c4a9b5c2ff03c373d78d2774e7ce SHA-1: 39ef015669dce99989b8540b13786321357db0f1 SHA-256: ff4d9ae3b450bf5ae39ea961321932a199933d64bb1b80daa023b88f6e588c67
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV and an ML classifier as malicious. It contains numerous embedded URLs pointing to various domains, many of which are identified as a link farm on disposable hosting. The primary URL, 'https://coretry.ru/uplcv?utm_term=orfox+tor+browser+for+android+download', suggests a lure to download software, likely malicious or unwanted. The PDF structure and extensive use of external links indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 5

  • 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.
  • 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://coretry.ru/uplcv?utm_term=orfox+tor+browser+for+android+download PDF link annotation
    • http://vuoncotichdep.com/upload/files/9442441024.pdfIn PDF document text
    • https://mintedimages.com/ckfinder/userfiles/files/wugatunemusimegegi.pdfIn PDF document text
    • https://ajambary.com/userfiles/file/daniwoxalusota.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/56053844185.pdfIn PDF document text
    • https://muzpony.de/obrazki/file/50541963096.pdfIn PDF document text
    • https://arhometutor.com/userfiles/file/galapewiribibefesu.pdfIn PDF document text
    • https://tour-paris-guide.com/cite_imgs/file/40746298091.pdfIn PDF document text
    • http://czechdidgeridoo.com/admin/upload/file/mafowufogogisubolat.pdfIn PDF document text
    • http://www.oomedia.com.tw/ckfinder/userfiles/files/78215178123.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/37517397231.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sosajobelanojamugem.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/dinirugikatifaf.pdfIn PDF document text
    • https://rugsdirect4u.com/uploadedfiles/file/zukopapefik.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/92161728771.pdfIn PDF document text
    • https://igk-lilienthal.de/downloads/wofujibagafo.pdfIn PDF document text
    • http://www.yemany.com/yemfiles/files/2957925572.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16139498c6cefa---zigetukawuribijopibazo.pdfIn PDF document text
    • https://newcar-rental.com/uploads/files/202109100318316805.pdfIn PDF document text
    • http://caycanhtuyhien.com/uploads/image/files/16973111626.pdfIn PDF document text
    • https://mtestbd.com/assets/uploads/files/gepufaxonoxagefepa.pdfIn PDF document text
    • http://szpitalstrzelin.pl/userfiles/files/xudomuwiv.pdfIn PDF document text
    • https://htijsr.com/userfiles/file/65159791991.pdfIn PDF document text
    • http://votejoedestefano.com/editorData/file/rupuvezifix.pdfIn PDF document text
    • http://www.petersonassoc.com/emailimages/file/55106729150.pdfIn PDF document text
    • https://xn--nmqu14inmf.com/upload/files/gixikepekoxigarij.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_off0000c1e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1E3 10700 bytes
SHA-256: 81225cce7c9b73aa5b5d374d4fe934f2180f4eae1a0f12fad89cac337b48387f
font_01_sfnt_off0000daa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA4 20252 bytes
SHA-256: 05b5ecdd3734647194788bf89ad5a912a303ca75a21d6b6766e88eee3cf0e1a7
font_02_sfnt_off00010f23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F23 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1