Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f1a731e32bbdcb2…

MALICIOUS

PDF

82.7 KB Created: 2021-09-17 13:13:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c51268cddd6ea48af027eff020677423 SHA-1: 86cde8ea7ec0426e2bbf5064563e540c6d95895b SHA-256: 5f1a731e32bbdcb2397eb1b8a5355577357295406d83a142dc5c03e9a293811f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are hosted on disposable or compromised domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards the use of embedded JavaScript for malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://caogenzhiben.com/filespath/files/20210902115249.pdf In PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/komolugevapobizamix.pdfIn PDF document text
    • http://superazs.ru/images/news/file/zomuxenate.pdfIn PDF document text
    • https://ladangmimpi.com/contents/files/37944570435.pdfIn PDF document text
    • http://worldcar.jp/userfiles/files/37297627392.pdfIn PDF document text
    • http://fotografieindex.nl/images/uploads/55917394167.pdfIn PDF document text
    • https://htapigroup3.com/contents/files/37688169989.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133fac758d01---jirakefuzawewewilarovu.pdfIn PDF document text
    • http://peoplefineart.com/assets/202109/files/20210909035626874674.pdfIn PDF document text
    • https://rijst.nu/userfiles/file/80283711537.pdfIn PDF document text
    • https://totalsewa.com/userfiles/file/gifefidaxakotukosazeli.pdfIn PDF document text
    • http://sinojjacob.com/userfiles/file/rumazazudovelunexojek.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/gepanok.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/xiwolij.pdfIn PDF document text
    • http://xn--90afqerdlt1f.xn--p1ai/admin/ckfinder/userfiles/files/29075799717.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/bulesujawelov.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/fuxalewisipepozegaka.pdfIn PDF document text
    • http://feynburg-uhren.de/uploads/xizunosarugelaxokebepu.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/9mdclup9i196vbi5dmavqhb9qv/fuvivavupepaniguxuwomagi.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/86253933660.pdfIn PDF document text
    • https://tmtteks.com/files/bivurafab.pdfIn PDF document text
    • http://jcnjl.com/userfiles/files/jawumujuf.pdfIn PDF document text
    • http://dentalweek.eu/userfiles/files/kanekasibedumugos.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/1d136170126decbaad7d36001655637b/82322790627.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=win7+home+basicPDF 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_off0000df4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f763.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF763 10436 bytes
SHA-256: 52fb8756990962655d5f6adc14b5f2662f360587bf3314e4ac122acab0940c74
font_02_sfnt_off00010ee3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EE3 18108 bytes
SHA-256: 20c98dba077bf341386b5a8c2aaf17f65699e92fdbe1ae1c1c71792642e95cd2