Malicious PDF — malware analysis report

Static analysis result for SHA-256 a95beb2fc277dd97…

MALICIOUS

PDF

80.9 KB Created: 2021-10-12 06:31:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5e1ea2f8d1a93993cb992f900c5c5ae5 SHA-1: 65c326bd336009805d3e5f70af102250f09bcb19 SHA-256: a95beb2fc277dd97a046c6e7f83676fbccd92ff5e15edd4f2e9b3745ee26f868
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133e584438a9---16214604500.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615eb39b48f54---21190174388.pdf
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16160798fc669f---35668608477.pdf
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/161491dc6412d9---kununozi.pdf
    • http://denge.aero/upload/files/23256153173.pdf
    • http://zae.me/datafiles/file/muzamoromolekip.pdf
    • https://marbeyoyun.com/calisma2/files/uploads/8272409080.pdf
    • http://canadanur.com/resimler/files/43183566970.pdf
    • https://argentinaproduct.com/ckfinder/userfiles/files/xedozekiluxedofi.pdf
    • https://avukat.dnsaktif.net/upload/files/857846843.pdf
    • http://blackivy.pl/userfiles/file/sijidalokifasedati.pdf
    • http://www.serenissimaservizi.com/files/96604756371.pdf
    • https://casaalu.com/luutru/files/xiwakosuvinutew.pdf
    • https://gymlesgeants.com/upload/editor/file/39756661490.pdf
    • http://jenan.com/ckfinder/userfiles/files/7593763659.pdf
    • http://kfbma.org/files/fck/file/meverozetenim.pdf
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/ea5jf38f9o06e1kcoa0qbufeii/9174127767.pdf
    • http://waxiangyuan.com/upload_fck/file/2021-9-19/20210919141525329519.pdf
    • http://eska-lift.ru/userfiles/file/18772505454.pdf
    • http://spreewaldatelier.de/img/editor/file/libegifefasukef.pdf
    • https://feedproxy.google.com/~r/Gsjc/~3/7xhmvLXWVJc/uplcv?utm_term=looking+glass+self+theory+definition
    • 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_off0000d70f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD70F 16792 bytes
font_01_sfnt_off0000ef21.bin
3819b780e274aaa9c4672730f80d877bdbe882ab9362df0a5ea42c8f3abebfd7
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF21 17984 bytes
font_02_sfnt_off00011d84.bin
53d1956d1812e8c576c2349d8ce96df240045bdb878928a1f290a0328e2cb8c7
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D84 10796 bytes