Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55861a3fe7915b5…

MALICIOUS

PDF

85.9 KB Created: 2021-07-21 08:03:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eb90572a79cd47698cc70dbbb650976d SHA-1: b6ba0f1ddef21c6d20875ac1c21c1cd8465202d4 SHA-256: a55861a3fe7915b5010fff1ff3481615978f870d222a4f53df6a155155cfb7ba
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection for Pdf.Phishing.Trojan. The numerous embedded URLs, many pointing to compromised WordPress sites and disposable hosting, suggest a link farm designed to redirect users to malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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
  • 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 http://thuduchouse.vn/pics/file/31475024178.pdf
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d0bf584426b---tetare.pdf
    • http://adabaskimerkezi.com/upload/file/gisefaxakiza.pdf
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/aakedqrql59p58kmtn1tldqea4/94388751041.pdf
    • http://bezagsecurity.cz/userfiles/fowujutew.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5ea5871d7---18680937123.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae90b94797---nobumegupatulo.pdf
    • http://steakclubhn.com/campannas/file/60479929521.pdf
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f588386465e---10094382906.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d63c081929e---25458268455.pdf
    • https://nguyenthelong.net/userfiles/files/51534419576.pdf
    • http://hodgesmageefamilyreunion.com/clients/c/c9/c95619ca3ec29dd030dc8935b97378d4/File/liwesilinimumilenevokep.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089b0bd4f636---25656162549.pdf
    • http://chatsworth72.com/clients/5/53/532ec3c8dc0e95779814939736d4df6d/File/6867864710.pdf
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b72553608---dorimunumifigenexug.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608728680b828---92055875308.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160f78b9576932---28911093207.pdf
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16092ce35aa486---nowezekixevusikefikovisep.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/fb3d86f5f83cc48747433a15b59bdc6f/towavebifus.pdf
    • https://martensmgt.com/business_school/uploads/file/fuputepabopijefufef.pdf
    • http://albertopizzetti.it/userfiles/files/memirod.pdf
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/36967628344.pdf
    • https://ottenburger.com/userfiles/file/runasuwasabipidipekemuku.pdf
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/07f2113c1514cdf91fc7fe737f448873/7940862098.pdf
    • http://icmasistemas.com/userfiles/files/gisakejun.pdf
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160739c98d6308---68104552272.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+accept+all+track+changes
    • 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_off0000ed50.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED50 16792 bytes
font_01_sfnt_off00010562.bin
0a83777621d9c25ee9104c2220b0cac388a31cc2f65106273bde8a6f897c7cf4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10562 16992 bytes
font_02_sfnt_off00013175.bin
f39f56980535b47653d9bd0a55e427a07de7c29047ff9061cecd35bc13cd0ba6
pdf-font-stream PDF embedded font (sfnt) at offset 0x13175 10728 bytes