Malicious PDF — malware analysis report

Static analysis result for SHA-256 553f0a25fbc83ad0…

MALICIOUS

PDF

90.7 KB Created: 2021-07-02 00:57:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2148529f58676e830ff35cecd642d392 SHA-1: 0378c7826ea9f9aaf6b58bf371f5d7cc8ff37456 SHA-256: 553f0a25fbc83ad0472935c6f1aa4422d7bb831679a5a755c8508abf285c3791
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress installations, suggesting an attempt to host and distribute malicious files. The ClamAV detection and ML classifier indicate malicious intent, likely phishing or malware delivery. The presence of embedded URLs and link farms on disposable hosting further supports this. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://infrive.ru/uplcv?utm_term=vision+board+template+printable
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c0a3e6dd169---84490496993.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160aab8bb4448b---vomutugolanameravalupipek.pdf
    • http://gustosandvic.com/ckfinder/userfiles/files/84596788793.pdf
    • http://mmprogetti.it/userfiles/files/43910356479.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c3e443197---98626601025.pdf
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071df0492a18---257034926.pdf
    • https://andrejc.si/files/file/24216243785.pdf
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa9135ee58c---935866721.pdf
    • http://ausafe.net/images/art/files/gowuzibevuzijel.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cffb41325d---xonijipovaz.pdf
    • https://henklinders.nl/henklinders/upload/files/76044869205.pdf
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/fc9e592cab7cb79265ed70d2840e0147/26906559199.pdf
    • http://palyavalaszto.hu/teszt/upload/file/52978908736.pdf
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608a0b568e6f0---32011547360.pdf
    • http://automozg.by/upload/editor/files/30717195484.pdf
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16089d0a9ab020---34308934043.pdf
    • http://carriewoodfamily.com/clients/5/5b/5b9f2fb360c4065436fb7fe1267c3612/File/bijig.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607050e2eef22---69424767711.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b48925842e7---34023753020.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/smfbq94eko9i8a25rehn8tkb01/94496862611.pdf
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b0e9cac3832---41104794309.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-4-30/20210430110918608142.pdf
    • https://islandsvefir.is/wp-content/plugins/super-forms/uploads/php/files/0s3knjo77um53898ir4kl7onn6/solomolofogosimam.pdf
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/a4b0eb26b18376719b9372d22f3953f9/pupubit.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160dd95363a2e1---10223967787.pdf
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c098103b5ff---508038167.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_off0000fac8.bin
3af553552d8ce824691d59454aa876e5bc067d1ce1bdd27ab219efba1890f5ef
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAC8 10664 bytes
font_01_sfnt_off00011301.bin
02bdb9b507efb150ce930146d6a95185d09a0bbaa974055c5fa4e3acc97001b6
pdf-font-stream PDF embedded font (sfnt) at offset 0x11301 18564 bytes
font_02_sfnt_off000143b8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x143B8 16792 bytes