Malicious PDF — malware analysis report

Static analysis result for SHA-256 773bc4047ec74a9f…

MALICIOUS

PDF

89.9 KB Created: 2021-06-29 11:09:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 78c67430661e35ce9e3a1073e794121c SHA-1: 81bee7b592a92498fdc3ef5b22faf640b0ed5ff0 SHA-256: 773bc4047ec74a9fbb77cbca0a721bf0484621278aaef583bdfb6394d74df4b0
216 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF is flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of multiple heuristics related to link farms and compromised CMS uploads suggests an attempt to distribute further malicious content or host it on compromised infrastructure. The 'SE_PASSWORD_ARCHIVE_LURE' heuristic indicates the document may be part of a multi-stage attack, potentially requiring a password to decrypt a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://coretry.ru/uplcv?utm_term=how+to+get+off+guided+access+without+password
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072b930c5f51---42285634871.pdf
    • http://cuhs1981.com/clients/8/82/82ca37c076ec4232796cb58ed009bb3a/File/24669229140.pdf
    • http://livingkaneohe.com/userimages/34061027443.pdf
    • https://planet-for-events.de/userfiles/file/27796194701.pdf
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/tiv23ot42glg1sf0a0ks4r1ftd/pemedaroruwapawar.pdf
    • https://ddshower.com/ckfinder/userfiles/files/30883151279.pdf
    • https://jagamimpi.org/contents//files/takawilezigonipe.pdf
    • https://k-newsletter.com/ckupload/files/lujaxafozexepudutiku.pdf
    • https://picinterior.com/ckfinder/userfiles/files/zaxebofewujamuti.pdf
    • http://jinistudy.com/_UploadFile/Images/file/41595821024.pdf
    • https://szaniterplaza.hu/ckfinder/userfiles/files/bexolajaxalixogixuj.pdf
    • http://georgekoldun.com/var/upload/file/webenubejituvofosezaj.pdf
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/2gph9fgnm0dnh95tnju59icr36/lojijenexato.pdf
    • http://gleneaglehoa.org/images/file/nujuzawigamuluxitopiju.pdf
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/ed13ae968e5f14b1114cfd546c144d9d/riguzagereposojik.pdf
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/cb6ljqe7o52ighq7gtvpukf39a/pogemotezorufoguwawanev.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6fc37425d5---46432201380.pdf
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/05q7p7kthqbdgecdq3io8q402a/wegutamu.pdf
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/cuecukoml944oln64e4vgiosnh/83530964232.pdf
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/579fbcf158c55f06f67bce0cd2c14e9b/pavovidewavorezivam.pdf
    • http://beerskiboot.com/img/upload/file/5806360823.pdf
    • https://maspacientes.es/wp-content/plugins/super-forms/uploads/php/files/qpasnql7743fr4ntaut9ufnt1o/zurimag.pdf
    • http://goref.ru/files/file/68868849825.pdf
    • http://busanpc1.com/upload/fckeditor/file/sesezixadilila.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_off0000f79e.bin
10fa74ee30d128a0b6fb295330240b2744635b51b0dfedc71582f796eb44d0d9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF79E 18012 bytes
font_01_sfnt_off000126eb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x126EB 16792 bytes
font_02_sfnt_off00013f02.bin
bbdd0a46d94e49306764682d2a0459a54ac5fa16d13a3b7cc7cce9319d69c668
pdf-font-stream PDF embedded font (sfnt) at offset 0x13F02 10928 bytes