Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1f35695e1451ecb…

MALICIOUS

PDF

85.6 KB Created: 2021-06-28 01:12:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 806d84e106a41f957534e28d53af6ff7 SHA-1: e0ebd1d9b48fc6b2c89f0ec623335373a30ef884 SHA-256: a1f35695e1451ecb4090adf256b0f0351e4e5562941dc8f4178eb9016c374a76
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing numerous links to other PDFs hosted on compromised websites, indicative of a link farm or phishing lure. The 'SE_CALLBACK_LURE' heuristic suggests a potential callback phishing or tech-support scam context. While no scripts were explicitly extracted, the presence of embedded URLs and the ML classifier's high confidence score point towards malicious intent, likely to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/0716af47f39a887daa4c5951f9ce1156/puxufaxutujumu.pdf
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/485dceb13be0012706085f83e40e3601/noriwodopenusubuxo.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb26d4234b---31093070344.pdf
    • http://bajajsports.com/userfiles/file/79164705611.pdf
    • http://beateromer.com/bilder/file/niragomem.pdf
    • http://imi.vc/upload/files/zonipigizategoko.pdf
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160c3f9cf17e94---89913598258.pdf
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160b765ef27c11---sufosawumevugumeto.pdf
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfec41d925---26368874008.pdf
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/1d61uia4dhlc762d0joef34b76/29296133756.pdf
    • https://p99.tw/pro_pic/files/81473037779.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b07034efad4---80232416739.pdf
    • https://felix-schulze.biz/wp-content/plugins/super-forms/uploads/php/files/24uptdsfvrr32kcvf5psd7m05o/pirivebibiwejuvew.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e391c10b8d---73967828043.pdf
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5ecbf43fd6---wogiwatuladujuvar.pdf
    • https://burkina-businessschool.com/business_school/uploads/file/86884357482.pdf
    • http://candientushinko.com/images/file/zosiwomilinonalev.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f047eedbe9---70349591903.pdf
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/3fbef86ff50b39a65ab07388a254948b/1843314265.pdf
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/juiv295tg72vn8h1rg1tsgqm21/82586654401.pdf
    • https://cardion.dk/gfx/fckimages/file/72593246106.pdf
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/jli3tpg76iu2838nsg8acdn8c0/51217620961.pdf
    • https://micsys.in/userfiles/file/2560649872.pdf
    • http://ctyrkolky-gamax.cz/data/dokumenty/pugukisulutoxab.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=s+pass+application+form
    • 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_off0000ebf7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF7 16792 bytes
font_01_sfnt_off0001040e.bin
3cc3874c8c64f324e86bedc78029ac7a2ca8a47bf8416d45baa0a6921e1ff0cb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1040E 10584 bytes
font_02_sfnt_off00011c27.bin
241ac653b6a5e57ce1dc53b0c6cd62d14027996ab103cfd5a176ae521e20c5f6
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C27 17248 bytes