Malicious PDF — malware analysis report

Static analysis result for SHA-256 55fc2b6a2b22b7fa…

MALICIOUS

PDF

89.2 KB Created: 2021-07-13 01:52:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f66388acf5a1651452f6d13f3469b4b4 SHA-1: 119cf68c6126ff9c06ac7244bfcf19cc1f76ca1e SHA-256: 55fc2b6a2b22b7fa89c4c090bc8c98530ccb00454b418656f69c4ae6c1a2646c
176 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting. The 'SE_CALLBACK_LURE' heuristic suggests a potential callback phishing or tech-support scam pretext, aiming to trick users into interacting with malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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 http://seoulmenu.com/uploads/files/64533869795.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb9a369d43---sajamilelu.pdf
    • http://retroldn.com/userfiles/file/8444367766.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cfcf451285---14448706062.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608076a78b7fe---17756361544.pdf
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/dve3a0ar41iao5km4fvp78j7n5/sotofimuj.pdf
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad76a350239---92996617468.pdf
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2320f6c5ca---8991577240.pdf
    • https://thegioidongphuc.net/ckfinder/userfiles/files/xiwogimemufivamumopajaxe.pdf
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/160c93feb88e36---58357008250.pdf
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/75bacfb0560f35bd7857ff3e9d74fb41/13709323301.pdf
    • https://newtop-eg.com/userfiles/file/vebozibi.pdf
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/69652be838b12e3f6af0a712401e9d8b/zixukufipebovetono.pdf
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/m84iuoo8s4jdjntnnm71tnlt7p/wutopimuzunug.pdf
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607818ca4655b---91629324275.pdf
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/790a110961a7f407e64b28cc4c90156c/34672992547.pdf
    • http://cbwmd.com/uploads/Files/16582241572.pdf
    • http://rauvuonsach.com/images/uploads/files/78151072021.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/jh7b8b3i5p4m5v24k6m67fps41/vevolemun.pdf
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/b836ab3a3c31018da167f1807a21b210/sopanovunobugakug.pdf
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb86aefa78---28336651676.pdf
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/kaulhhmbqsrt33ufqbsuntqqvi/duxudituk.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=a+parallel+plate+condenser+with+plate+area+a
    • 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_off0000f71a.bin
3920ed5afbb15e1af9250793761d58fe79cfd7fe4ec6033298942a1b667fc7c4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF71A 10676 bytes
font_01_sfnt_off00010f98.bin
d2046c5c8f5981aca7f44f646807581b8c5fe4a7c6f03e34fece5939cbc1386a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F98 17928 bytes
font_02_sfnt_off00013f10.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13F10 16792 bytes