Malicious PDF — malware analysis report

Static analysis result for SHA-256 2818ce42ac7b5361…

MALICIOUS

PDF

81.4 KB Created: 2021-09-21 04:21:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 731e48638d02cc1a303328b91e0adfdd SHA-1: ca79fff28200c542bfdcd501581dd5e211cf581a SHA-256: 2818ce42ac7b5361f8a5d6b62c465f56967495be4f59e87c09e6e59bf527475f
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URIs, many of which point to compromised websites or disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is unreadable, but the heuristics and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://medvor.ru/uplcv?utm_term=oldboy+korean+movie+online
    • https://kristinanamaste.eu/files/31485766454.pdf
    • http://metalzilemboeventi.com/userfiles/files/suwolutajuxijalatamek.pdf
    • http://gro-felix.si/uploads/4463731443.pdf
    • http://greddy.com/admin/common/ckfinder/userfiles/File/9728339918.pdf
    • https://aspirans.com/files/file/77619874893.pdf
    • https://greenlandpark.com/uploads/files/jazifokoporal.pdf
    • http://stihoplet.by/upload/editor/files/boxosolibuka.pdf
    • http://nhasachthunam.com/upload/files/84194423220.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e98366df2a---78933084150.pdf
    • https://hexema.com/FCKeditor/file/11637103461.pdf
    • https://dpengineerindia.com/admin/userfiles/file/63239426374.pdf
    • http://140.121.161.111/ckfinder/userfiles/files/muvomuzaf.pdf
    • http://mya1fc.com/files/ckuploads/files/fepela.pdf
    • http://chipublichouse.com/ckfinder/userfiles/files/51658826252.pdf
    • https://machnik.net/ckfinder/userfiles/files/vomizaleresosivuwemuxojas.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c115b08765---kagibuwobodamifovige.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd45b012dd---26201769699.pdf
    • http://vhz.cz/user-files/solomimejapulokewolopazif.pdf
    • http://jogagongu.pl/userfiles/file/9343068151.pdf
    • http://strandedtattoo.info/file/22340716301.pdf
    • http://tootingtaxi.com/survey/userfiles/files/64972181483.pdf
    • http://brcassociati.com/userfiles/files/10888135660.pdf
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/16148de3e6eff1---gajasokaxikule.pdf
    • http://kengosushionlineorder.com/uploads/files/96663778840.pdf
    • https://kudamatsu.org/userfiles/file/suwawamizigobetax.pdf
    • http://rkenterprisesonline.com/FCKeditor/file/suruzipaletogimolukivi.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc01.bin
30c7b7bae0e82ecfd3b205b170986ab7d9c69771c40359defc80141116306fd2
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC01 10580 bytes
font_01_sfnt_off0000f40f.bin
11e3b6299310995a91f3b1ec0a4fa3de99d040242f4e1169f95f1fb4988168d4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF40F 17076 bytes
font_02_sfnt_off00011fdd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FDD 16792 bytes