Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b9243e089202447…

MALICIOUS

PDF

83.1 KB Created: 2021-09-17 07:47:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 343fd2deb6f9d87e40c37a1a50ab9323 SHA-1: 6f01c044cabe8978160ea37b9b0412311caf176f SHA-256: 1b9243e089202447cfbbd426ddb2fa3d08f420d104553769dffff5c3d2bbb9ac
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high-confidence heuristic firing for a PDF link to an algorithmically-generated URL, indicating a malicious intent to redirect the user. The presence of multiple links to PDF files hosted on various domains, some flagged as disposable link farms, further supports a phishing or malware distribution scheme. The ClamAV detection as 'Pdf.Phishing.Trojan' strongly confirms the malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://coherence.cz/userfiles/file/toradoziderijotavulomape.pdf In PDF document text
    • https://rts-wm.com/ckfinder/userfiles/files/64100272699.pdfIn PDF document text
    • https://andrejc.si/files/file/87438893944.pdfIn PDF document text
    • http://wonsakai.com/uploads/files/49173813003.pdfIn PDF document text
    • http://w-mill.jp/images/file/wezozijawerulugo.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/vruq4hsnin9ndecslcr8mfc298/87642314824.pdfIn PDF document text
    • http://nathulaldasptti.com/ckeditor/ckfinder/userfiles/files/17360444684.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/50377473578.pdfIn PDF document text
    • https://goodnest.info/tctt/sites/aaa/file/56244559444.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/98795172835.pdfIn PDF document text
    • http://wieswioska.pl/userfiles/file/95633891156.pdfIn PDF document text
    • http://lohoithaiduong.com/uploads/files/ninisem.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614406564d686---fomibekufasulegiguwotedux.pdfIn PDF document text
    • https://sport-jicin.cz/dokumenty/38447409860.pdfIn PDF document text
    • https://cevhertemizlik.com/userfiles/files/movetolugemujepewowo.pdfIn PDF document text
    • http://moscowballet.ru/userfiles/file/86487326874.pdfIn PDF document text
    • https://almuhja.com/ckfinder/userfiles/files/pefepedabosuxozijob.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/62237330098.pdfIn PDF document text
    • http://thepnguyentran.com/media/ftp/file/lunidomixokug.pdfIn PDF document text
    • http://tele-klass.ru/i/upload/files/nogikererej.pdfIn PDF document text
    • http://blueyee.com/upload/file/070400225158.pdfIn PDF document text
    • http://loveperfectionschool.com/upload/file/58145100233.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=download+tubemate+2020PDF link annotation
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/pasazar.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_off0000e22f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE22F 17032 bytes
SHA-256: 9d4c26d7489b17c8c45e3b22047145b14cb68177ec3c25ddab22f6d18f35b80d
font_01_sfnt_off00010e3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E3E 10620 bytes
SHA-256: 23004ff7a7f86a24338bdaf09f0d40eadf5f9e5468d68296b2536ca9185edee3
font_02_sfnt_off0001269b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1269B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1